TW202412978A - Welding method and laser processing device - Google Patents

Abstract

A welding method for welding metals with a laser is provided with which it is possible to shorten the processing time while maintaining satisfactory weld quality. In the welding method, end surfaces of a first member and a second member are placed so as to butt against each other and disposed so that the end surfaces face a laser device 1 and the end surfaces are welded with laser light. The method is characterized by comprising a first step, in which the first member is irradiated with laser light to form a first molten portion, a second step, in which the second member is irradiated with laser light to form a second molten portion, and a third step, in which after the first molten portion and the second molten portion have been bonded to each other, the bonded, first and second molten portions are irradiated with laser light to form one molten portion, the laser light being composed of first laser light and second laser light, which differ in wavelength from each other.

Description

Welding method and laser processing device

The present invention relates to a welding method and a laser processing device for welding metal using laser light.

As one of the technologies for metal welding, laser welding using laser light is used. When comparing laser welding with other welding technologies, it is possible to weld the workpiece with energy that is highly concentrated by a focusing lens, and the welding quality is high and it is suitable for fine welding. In recent years, this type of laser welding has been used in the manufacture of stators (stators) for motors incorporated in hybrid vehicles and electric vehicles. The stator is composed of a stator core and a plurality of segment coils, and the plurality of segment coils are installed in the slots of the stator core; the stator is joined to each other by laser welding at the ends of the corresponding segment coils. Usually, each segmented coil uses a flat conductor; the welding surface is fine up to several square millimeters (mm²), so it is suitable for laser welding. However, in the front end welding process of the flat conductor, there will be the following situation: due to the influence of the deviation of processing precision, the precision of the fixing jig mechanism, the thickness of the conductor coating, etc., a gap and step difference will be generated when the front end is connected. In this case, when the laser is continuously irradiated across the two flat conductors, the following situation will occur: laser leakage will occur from the gap and the laser will be irradiated to the coating at the bottom of the flat conductor, resulting in carbonization and poor insulation. Patent document 1 discloses a flat wire front end welding process technology, which discloses that: even if there is a gap between two flat wires, in order to prevent laser leakage, the gap is filled with molten metal while welding. In particular, when laser irradiation starts, in order to prevent a large amount of sputtering due to the high energy density at the welding surface, welding is performed to suppress the scanning track of the energy density at the beginning of irradiation. Patent document 2 discloses a welding method for preventing laser light from leaking from the gap of an electrical conductor when the ends of an electrical conductor are joined together. Specifically, two adjacent electrical conductors are welded separately to form molten parts respectively. Thereafter, a pressing force is applied by a pressing mechanism to bring the ends closer to each other, thereby joining the molten parts to each other. In this way, the ends of the electrical conductors can be joined together without having to butt them together with high precision. [Prior art document] [Patent document]

[Patent Document 1] Japanese Patent Publication No. 2019-181506. [Patent Document 2] Japanese Patent Publication No. 2020-142257.

[The problem that the invention wants to solve]

However, when the laser light is continuously scanned across two flat lines as in Patent Document 1, a large amount of spatter will occur when crossing the step difference. In addition, when the laser light is scanned equally across the left and right flat lines without considering the step difference, the height of the molten part will be different on the left and right, destroying the balance and reducing the welding strength. Furthermore, when the technology of Patent Document 2 is used to press the ends together and combine the molten parts, there is also the possibility that the already combined molten parts will tilt and the molten parts will drip from the end surface, making it difficult to form a beautiful molten ball. When the molten ball formed at the front end tilts and drips, there will be a problem that the required welding quality cannot be met and the welding strength is reduced. Therefore, the present invention is developed in view of the above-mentioned problems, and its purpose is to provide a welding method and a laser processing device, which can ensure good welding quality and welding strength in the welding method for welding the front end of a flat conductor without causing laser leakage from the gap of the flat conductor. [Means for solving the problem]

In order to solve the above-mentioned problem, the present invention is a welding method, which is used to arrange the end faces of the first component and the second component after the ends are butted against each other to face the laser processing device, and weld the end faces by laser light; the welding method comprises: a first step, irradiating the first component with the laser light to form a first molten portion; a second step, irradiating the second component with the laser light to form a second molten portion; and a third step, when the first molten portion and the second molten portion are combined, irradiating the combined first molten portion and the second molten portion with the laser light to form a molten portion; the laser light is composed of a first laser light and a second laser light having different wavelengths. [Effect of the invention]

According to the present invention, even if a gap is generated when the front end of the flat wire is butted, the third step is performed after the two molten parts are connected by the first step and the second step, thereby preventing the laser from leaking from the gap and causing damage to the lower part of the flat conductor. In addition, by irradiating the molten parts connected in the third step with laser, the molten parts can be made uniform, thereby forming a beautiful molten ball that is symmetrical on both sides.

[Implementation Form 1] (1) Overall structure of laser processing device 1 FIG. 1 is an external view showing the structure of laser processing device 1, and FIG. 2 is a diagram showing the functional structure of laser processing device 1. As shown in FIG. 1 and FIG. 2 , the laser processing device 1 is composed of the following components: a first oscillator 2 (blue semiconductor laser) for oscillating the first laser light L1; a second oscillator 3 (infrared fiber laser) for oscillating the second laser light L2; a hybrid galvanometer scanner 10 for aligning the optical axes of the first laser light L1 and the second laser light L2 and displacing the irradiation positions of the first laser light L1 and the second laser light L2 relative to the workpiece W; an image processing unit 9 for capturing an image of the workpiece W and analyzing the configuration of each flat wire; a workpiece setting table (work set The workpiece W is placed on the workpiece placement stage 11, and can move the placed workpiece W in three-dimensional directions (x, y, z) and in a rotational direction (θ) around the z axis; the fixing fixture 15 fixes the workpiece W on the workpiece placement stage 11; the control personal computer 12 controls the entire laser processing device 1; the PLC (Programmable Logic Controller) 13 controls each machine in cooperation with the control personal computer 12; and the laser controller 14 controls the actions of the first oscillator 2 and the second oscillator 3.

In addition, the image processing unit 9 is composed of an illumination device 101, a camera device 102, and a controller 103; the controller 103 is built into the control panel 100 of FIG. 1. The control panel 100 is a computer built into the laser processing device 1; specifically, in addition to the controller 103 with the image processing unit 9 built in, a PLC 13 and a laser controller 14 are also built in. In addition, the workpiece mounting table 11 is composed of the following components: a base 11a; an x-axis table 11x, which is a mechanism for moving the workpiece W in the x-axis direction; a y-axis table 11y, which is a mechanism for moving the workpiece W in the y-axis direction; a θ-axis table 11θ, which is a mechanism for rotating the workpiece W around the z-axis; and a z-axis table 11z, which is a mechanism for moving the workpiece W and the hybrid galvanometer scanner 10 relatively in the z-axis direction.

(2) Regarding laser light The first laser light L1 and the second laser light L2 oscillated by the first oscillator 2 and the second oscillator 3 are respectively transmitted by optical fibers and injected into the hybrid galvanometer scanner 10. Moreover, the first laser light L1 and the second laser light L2 are overlapped by the hybrid galvanometer scanner 10 in a manner that the optical axes are consistent. The overlapped first laser light L1 and the second laser light L2 are reduced to a predetermined diameter and then irradiated onto the opposite workpiece W. In this way, in the laser processing device 1, the workpiece W is irradiated with the two first laser lights L1 and the second laser lights L2 to perform welding. As the first laser light L1, a blue semiconductor laser connected to a multi-mode fiber is used. The first laser light L1 only needs to have a wavelength of 300nm to 600nm, and a green laser can be used instead of a blue laser. In addition, the output power of the first laser light L1 is preferably 500W to 3kW; as an example, it is 600W in this embodiment.

As the second laser light L2, a near-infrared single-mode fiber laser with a wavelength of 780nm to 1100nm is used. That is, the wavelengths of the first laser light L1 and the second laser light L2 are different from each other, and the wavelength of the first laser light L1 is shorter than the wavelength of the second laser light L2. The output power of the second laser light L2 is preferably 500W to 2kW; as an example, it is 1.5kW in this embodiment. In this embodiment, the first laser light L1 uses multi-mode, and the second laser light L2 uses single-mode. Compared with the first laser light L1, the second laser light L2 is a spot light with a small focusing diameter. Therefore, using a single-mode fiber laser as the second oscillator 3 can effectively generate the second laser light L2 with a small beam diameter and a high peak energy intensity.

(3) Hybrid galvanometer scanner 10 Next, the hybrid galvanometer scanner 10 is described in detail. The hybrid galvanometer scanner 10 shown in FIGS. 3 to 5 comprises: a combiner section 4 for superimposing the first laser light L1 and the second laser light L2 supplied from the first oscillator 2 and the second oscillator 3 on the same optical axis; a focus shifter section 6 located downstream of the combiner section 4 for adjusting the focal distance of the first laser light L1 and the second laser light L2 superimposed on the same optical axis; and a galvanometer scanner section 8 located downstream of the focus shifter section 6 for shifting the direction of the optical axis of the first laser light L1 and the second laser light L2 toward the workpiece W.

As shown in FIG3 , the synthesizer unit 4 has, for example: lenses (collimation lenses, etc.) 31 and 32, which collimate the first laser light L1 and the second laser light L2 supplied from the first oscillator 2 and the second oscillator 3, respectively; and necessary mirrors (including beam splitters, half mirrors, synthesizers, etc.) 33 and 34, which are used to align the optical axes of the first laser light L1 and the second laser light L2 that have passed through the lenses 31 and 32. Of course, the synthesizer unit 4 may also have optical elements, optical fibers, and other components other than those described above. In addition, three or more laser lights with different wavelengths can also be superimposed in the synthesizer unit 4. As shown in FIG4 , the focus shifter section 6 has: a lens (concave lens, especially a biconcave lens) 41 (hereinafter also referred to as concave lens 41, biconcave lens 41), which expands the diameter of the first laser light L1 and the second laser light L2 overlapped in the synthesizer section 4; and lenses (plural convex lenses, especially plano-convex lenses as collimating lenses and focusing lenses, etc.) 42, 43 (hereinafter also referred to as convex lenses 42, 43, collimating lens 42, focusing lens 43), which reduce the diameter of the first laser light L1 and the second laser light L2 that have passed through the lens 41. Of course, the focus shifter section 6 may also have optical elements, optical fibers, and other components other than those described above.

The focus shifter unit 6 is capable of adjusting the focus distance F of the first laser light L1 and the second laser light L2 from the synthesizer unit 4. Therefore, in the example shown in FIG. 4 , a driving mechanism such as a linear motor carriage supports at least one of the concave lens 41 and/or the convex lens 42 and enables the concave lens 41 and the convex lens 42 to move forward and backward along the optical axis so that the relative distance D between the first laser light L1 and the second laser light L2 along the optical axis between the concave lens 41 and the convex lens 42 can be adjusted. Incidentally, the condenser lens 43 at the end may not move forward and backward along the optical axis. As shown in (A) of FIG. 4 , the narrower the relative distance D between the concave lens 41 and the convex lens 42, the longer the focal distance F of the first laser light L1 and the second laser light L2 that have passed through the lenses 41, 42, and 43 of the focus shifter unit 6. That is, the focal points of the first laser light L1 and the second laser light L2 are away from the lens 43 at the end of the focus shifter unit 6.

On the contrary, as shown in (B) of FIG. 4 , the wider the relative distance D between the concave lens 41 and the convex lens 42, the shorter the focal distance F of the first laser light L1 and the second laser light L2 that have passed through the lenses 41, 42, and 43 of the focus shifter section 6. That is, the focal points of the first laser light L1 and the second laser light L2 are close to the lens 43 at the end of the focus shifter section 6. In addition, in the lenses 41, 42, and 43, color aberration inevitably occurs as a general physical law (the refractive index of light depends on the wavelength of the light). Therefore, when a laser beam with multiple laser beams of different wavelengths is to be superimposed on the workpiece W, the irradiation position of a certain wavelength laser beam and the irradiation position of other wavelength laser beams that should be superimposed on the irradiation position of the laser beam will deviate on the workpiece. Because of this deviation, there is a concern that the desired laser treatment or processing result cannot be obtained. Therefore, the position of the lens 31 and/or lens 32 through which the first laser beam L1 and the second laser beam L2 output from the first oscillator 2 and the second oscillator 3 pass is actually adjusted to match the focus of the superimposed first laser beam L1 and the focus of the second laser beam L2.

As shown in FIG. 3 and FIG. 5 , the galvanometer scanner unit 8 is a known component, and is used to rotate the mirrors 81 and 83 through the driving mechanism of the mirrors 82 and 84 such as a servo motor and a stepping motor. The mirrors 81 and 83 are used to reflect the first laser light L1 and the second laser light L2 from the focus shifter unit 6. In short, the galvanometer scanner unit 8 can displace the directions of the optical axes of the first laser light L1 and the second laser light L2 reflected by the mirrors 81 and 83. The galvanometer scanner unit 8 in the present embodiment comprises: mirrors 83 and 84, which are X-axis galvanometer scanners for changing the optical axes of the first laser light L1 and the second laser light L2 toward the workpiece W along the X-axis direction on the workpiece W; and mirrors 81 and 82, which are Y-axis galvanometer scanners for changing the optical axes of the first laser light L1 and the second laser light L2 toward the workpiece W along the Y-axis direction on the workpiece W; the galvanometer scanner unit 8 scans the first laser light L1 and the second laser light L2 in the XY two-dimensional direction on the workpiece W, thereby two-dimensionally controlling the irradiation positions of the first laser light L1 and the second laser light L2 on the workpiece W.

As a feature of the hybrid galvanometer scanner 10 of this embodiment, the adjustment of the focal distance F by the focus shifter unit 6 and the displacement of the direction of the optical axis by the galvanometer scanner unit 8 can be synchronized. The closer the angle θ of the optical axis of the first laser light L1 and the second laser light L2 through the mirrors 81 and 83 of the galvanometer scanner unit 8 to the workpiece W is to the vertical, the shorter the optical path length from the mirror 83 to the workpiece W is. Therefore, the focus shifter unit 6 and the galvanometer scanner unit 8 are synchronously controlled in such a way that the focal distance F embodied by the focus shifter unit 6 is shortened as the angle θ of the optical axis of the first laser light L1 and the second laser light L2 to the workpiece W is to the vertical (90°).

On the contrary, the more the angle θ of the optical axis of the first laser light L1 and the second laser light L2 passing through the mirrors 81 and 83 of the galvanometer scanner unit 8 relative to the workpiece W is tilted from the vertical, the longer the optical path length from the mirror 83 to the workpiece W is. Therefore, the focus shifter unit 6 and the galvanometer scanner unit 8 are synchronously controlled in such a way that the more the angle θ of the optical axis of the first laser light L1 and the second laser light L2 relative to the workpiece W is tilted (the farther it is from 90°), the longer the focal distance F embodied by the focus shifter unit 6 is. By synchronously controlling the lenses 41 and 42 of the focus shifter unit 6 and the mirrors 81 and 83 of the galvanometer scanner unit 8 described above, the first laser light L1 and the second laser light L2 can be irradiated to any part of the workpiece W, and the focus of the first laser light L1 and the second laser light L2 can be accurately aligned with the desired processing target surface of the workpiece W.

It is expected that there is no lens (fθ lens, etc.) between the mirrors 81 and 83 of the galvanometer scanner unit 8 and the workpiece W that is useful for passing the first laser light L1 and the second laser light L2. In this way, the problem of chromatic aberration generated when the first laser light L1 and the second laser light L2, which have been manipulated in the direction of the optical axis by the galvanometer scanner unit 8, pass through the lens can be reliably avoided. That is, there will be no deviation between the position where the first laser light L1 of a certain wavelength hits the workpiece W and the position where the second laser light L2 that has overlapped with the position hits the workpiece W. Therefore, the desired laser processing or processing result can be obtained. However, as long as the chromatic aberration is only to the extent that the deviation of the irradiation position of each of the first laser light L1 and the second laser light L2 can be ignored, it will not hinder the existence of a certain lens between the mirrors 81, 83 of the galvanometer scanner unit 8 and the workpiece W for allowing the first laser light L1 and the second laser light L2 to pass through.

In addition, the hybrid galvanometer scanner used in this embodiment is not limited to the structure described above. The biconcave lens 41, the collimating lens 42, and the focusing lens 43 belonging to the focus shifter section 6 are generally located downstream of the mirrors 33 and 34 belonging to the synthesizer section 4, but the arrangement of the mirrors 33, 34, lenses 41, 42, and 43 belonging to these optical elements is not limited to the arrangement shown in FIG. 3. FIG. 6 shows a hybrid galvanometer scanner 10a belonging to a variation. The hybrid oscillator scanner 10a has a biconcave lens 41 and a collimating lens 42 arranged on the optical axis of the first laser light L1 output from the first oscillator 2 and the optical axis of the second laser light L2 output from the second oscillator 3. In short, there are two biconcave lenses 41 and two collimating lenses 42.

Furthermore, the first laser light L1 and the second laser light L2 that have passed through the double concave lens 41 and the collimating lens 42 are overlapped with each other through the mirrors 33 and 34 that are elements of the synthesizer unit 4, and finally are focused through the focusing lens 43 and input to the galvanometer scanner unit 8. The hybrid galvanometer scanner 10a shown in FIG6 is also capable of adjusting the relative distance D between the optical axes of the first laser light L1 and the second laser light L2 between the concave lens 41 and the convex lens 42, similarly to the hybrid galvanometer scanner 10 in FIG3. Therefore, a suitable driving mechanism such as a linear motor carriage can support at least one of the concave lens 41 and/or convex lens 42 on the optical axis of each of the first laser light L1 and the second laser light L2 and can move forward and backward along the optical axis. For example, the concave lens 41 on the optical axis of the first laser light L1 and the concave lens 41 on the optical axis of the second laser light L2 are controlled simultaneously with a single axis, and these concave lenses 41 can move forward and backward along the optical axis. The position of the convex lens 42 on the optical axis of the first laser light L1 and the optical axis of the second laser light L2 is pre-adjusted in accordance with the wavelength of the first laser light L1 and the second laser light L2.

The adjustment of the relative distance D described above, in other words, can also synchronize the adjustment of the focal distance F by the focus shifter unit 6 and the displacement of the direction of the optical axis by the galvanometer scanner unit 8. In the example shown in FIG. 3 , after the first laser light L1 and the second laser light L2 of different wavelengths are overlapped by the mirrors 33 and 34 of the synthesizer unit 4, the focal distances of the first laser light L1 and the second laser light L2 are adjusted by the lenses 41, 42, and 43 of the focus shifter unit 6. In contrast, in the variation shown in FIG6 , after adjusting the focal distances of the first laser light L1 and the second laser light L2 by the lenses 41 and 42 of the focus shifter unit 6, the first laser light L1 and the second laser light L2 are overlapped by the lenses 33 and 34 of the synthesizer unit 4. Thus, the occurrence of chromatic aberration in the lenses 41 and 42 can be well avoided, and the first laser light L1 and the second laser light L2 can be irradiated to the desired irradiation position on the workpiece W with better precision using the galvanometer scanner unit 8.

As a further variation, a hybrid galvanometer scanner 10b is shown in FIG7. In this variation, a biconcave lens 41, a collimating lens 42, and a focusing lens 43 are arranged on the optical axis of the first laser light L1 output from the first oscillator 2 and the optical axis of the second laser light L2 output from the second oscillator 3. In short, there are two biconcave lenses 41, collimating lenses 42, and focusing lenses 43. Furthermore, the first laser light L1 and the second laser light L2 that have passed through the biconcave lens 41, the collimating lens 42, and the focusing lens 43 are overlapped with each other through the mirrors 33 and 34 that are elements of the synthesizer unit 4, and then input to the galvanometer scanner unit 8.

The hybrid galvanometer scanner 10b shown in FIG7 is also capable of adjusting the relative distance D between the concave lens 41 and the convex lens 42 along the optical axis of the first laser light L1 and the second laser light L2, similarly to the hybrid galvanometer scanner 10 in FIG3. Therefore, a suitable driving mechanism such as a linear motor carriage can support at least one of the concave lens 41 and/or the convex lens 42 on the optical axis of each of the first laser light L1 and the second laser light L2 and can move forward and backward along the optical axis. For example, the concave lens 41 on the optical axis of the first laser light L1 and the concave lens 41 on the optical axis of the second laser light L2 are controlled simultaneously with a single axis, and these concave lenses 41 can move forward and backward along the optical axis. The positions of the convex lens 42 on the optical axis of the first laser light L1 and the optical axis of the second laser light L2 are pre-adjusted in accordance with the wavelengths of the first laser light L1 and the second laser light L2.

The adjustment of the relative distance D described above, in other words, can also synchronize the adjustment of the focal distance F by the focus shifter unit 6 and the displacement of the direction of the optical axis by the galvanometer scanner unit 8. In the variation shown in FIG. 7 , after adjusting the focal distances of the first laser light L1 and the second laser light L2 by the lenses 41, 42, and 43 of the focus shifter unit 6, the first laser light L1 and the second laser light L2 are overlapped by the lenses 33 and 34 of the synthesizer unit 4. In this way, the occurrence of chromatic aberration in the lenses 41, 42, and 43 can be well avoided, and the galvanometer scanner unit 8 can be used to irradiate the first laser light L1 and the second laser light L2 to the desired irradiation position on the workpiece W with better precision.

(4) Description of the workpiece W Next, the workpiece W to be welded is described using FIGS. 8 to 10. FIG. 8 is a perspective view showing the schematic structure of a stator 50 belonging to a stator in a motor of an electric vehicle or the like. As shown in FIG. 8 , the stator 50 has a stator core 51 having a substantially cylindrical shape and a plurality of flat wires (segmented coils) 52. The flat wires 52 are conductors (wires) having a rectangular cross-section. Usually, the flat wires 52 are components made of pure copper, but they may also be made of a metal material having a high electrical conductivity, such as an alloy having copper as a main component, an alloy consisting of copper and aluminum, etc. The end of each flat wire 52 protrudes from the upper end of the stator core 51; the laser processing device 1 laser welds the ends of two flat wires 52 that are radially adjacent to the stator core 51 to each other.

In the front end welding process of the flat wire 52, the insulating coating on the front end side is peeled off, and the front ends of the two corresponding flat wires are butted. Then, laser light is irradiated toward the butted end faces. At this time, the following situation may occur: due to the deviation of the processing precision of each flat wire, the mechanical precision of the fixing jig 15, the insertion condition toward the groove 54, etc., a gap (gap, space) and position deviation are generated when the front ends of the two flat wires are butted. In the example of (a) in Figure 9, a gap is left between the two flat wires 52. In the example of (b) in Figure 9, the two flat wires 52 are deviated in the y-axis direction. In the example of (c) in Figure 9, the two flat wires 52 are spaced in the x-axis direction and deviated in the y-axis direction, and rotated in the θ direction.

When there is a gap (gap, void) or a large positional deviation between the two corresponding flat wires 52, the following situation may occur: laser leakage occurs from the gap or the deviated part, and the laser light is irradiated to the coating part at the bottom of the flat wire, thereby causing carbonization and poor insulation. In addition, even in the case where there is a positional deviation in the y-axis direction but no laser leakage occurs, if the laser light is irradiated across the two flat wires 52 without considering the countermeasures for the positional deviation, there will be a problem that the molten part deviates and tilts, thereby reducing the welding strength. In addition, as shown in Figure 10, when the front ends of the two flat wires 52 are connected, a step difference Δz may occur due to the deviation in the height direction (z direction). In addition, a certain gap (gap, void) Δxy is generated due to the thickness of the insulating coating part. In the following, the step difference between the two flat wires 52 in the z direction is recorded as Δz, and the distance in the xy plane is recorded as Δxy.

In this way, when the corresponding flat wires have a step difference in the z-axis direction, a large amount of spattering may occur when the laser light crosses the step difference. In addition, when the laser light is scanned equally across the left and right flat wires without considering the step difference, the height of the molten part will be different on the left and right, destroying the balance, and the welding strength will be reduced. Therefore, the laser processing device 1 of this embodiment performs welding processing even when there is a gap, position deviation, or a step difference in the z-axis direction between the two corresponding flat wires 52. The welding processing is used to suppress the occurrence of laser leakage and the reduction of welding strength.

(5) Regarding the image processing unit 9 In the welding of the stator coil, in order to properly irradiate the laser on the flat wire of several millimeters, it is necessary to accurately measure the position of the flat wire. Therefore, in the laser processing device 1, the center position and height relative to the front end of the plurality of flat wires 52 are measured by image analysis performed by the image processing unit 9. In addition, when the center position is measured by image analysis, when the flat wires are close to or abutting each other, the boundary line becomes unclear, and it is difficult to accurately determine the position of each flat wire. Therefore, even in the case where the flat wires are close to or abutting each other, the image processing unit 9 of this embodiment can accurately measure the center position of each flat wire 52. The following is a detailed description of the measurement method.

As shown in FIG. 11 , the image processing unit 9 includes: an illumination device 101 for irradiating illumination light to the workpiece W; a camera 102 for photographing the workpiece W under the illumination of the illumination device 101; and a controller 103 for measuring the center position and height of each flat line 52 contained in the workpiece W using the image data photographed by the camera 102. The illumination device 101 and the camera 102 are illumination devices and three-dimensional cameras suitable for pattern projection method; the illumination device 101 projects a plurality of stripe patterns (strip-shaped patterns) onto the workpiece W from a plurality of different directions, and the camera 102 receives the reflected light of the workpiece W using an image sensor such as a CMOS (Complementary Metal-Oxide Semiconductor). The controller 103 analyzes the changes in the pattern between the projected light and the reflected light to generate a three-dimensional image.

As shown in FIG11 , the controller 103 includes a memory 104 and a processor 105. A measurement program 111 and a critical value 112 are pre-stored in the memory 104. The critical value 112 may also be included in the measurement program 111. In addition, the memory 104 stores a coordinate table 113 generated by the processor 105. The processor 105 executes the measurement program 111 to measure the center position and height of all the flat wires 52 contained in the workpiece W, and generates a coordinate table 113 (CSV (comma separated values) data).

Here, the center position and height measured by the controller 103 are explained using FIG. 12 and FIG. 13. In the example of FIG. 12, the two flat wires 52 are deviated in the x-axis direction, the y-axis direction, and the θ direction. In the example of FIG. 13, the case where the two flat wires 52 are deviated in the x-axis direction and there is a step difference in the z-axis direction is used as an example for explanation. In addition, for the convenience of explanation, one flat wire 52 is recorded as "A pin" and the other flat wire 52 is recorded as "B pin". The controller 103 measures the coordinates (x, y, z, θ) of the center of the welding surface 52a for the A pin. These coordinates are recorded as "A pin coordinates". Similarly, the coordinates (x, y, z, θ) of the center of the welding surface 52a are also measured for the B pin. These coordinates are recorded as "B pin coordinates". In addition, the controller 103 calculates the coordinates (x, y, z, θ) of the middle point between the A pin and the B pin. This coordinate is recorded as "AB pin coordinates". Here, as an example, the origin (reference point) of the xyz orthogonal coordinate system is set as the center point of the upper surface of the workpiece setting table 11 on which the workpiece W is placed. In addition, θ is the angle around the z axis on the xy plane. In addition, θ can also be measured by image processing, but as long as the structure of the stator 50 that is the object of welding is known, the value derived from the structure of the stator 50 can also be used instead of the measurement by image processing.

The controller 103 measures the coordinate values of each flat wire and the coordinate value of the center point for each pair of flat wires 52 to be welded. The coordinate table 113 is recorded to display the measurement results, and the coordinate table 113 is stored in the memory 104. (6) Controlling the personal computer 12 As shown in FIG. 14 , the controlling personal computer 12 is composed of a control unit 201, a memory unit 202, an input unit 203, a communication unit 204, and a display unit 205. Specifically, the control personal computer 12 is a computer system having the following hardware resources: CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), display unit, communication interface, keyboard, mouse and other input devices. In the welding process using a galvanometer scanner, the control personal computer is also called a "galvanometer scanner personal computer".

The control unit 201 is composed of a CPU and a RAM belonging to a working memory. The memory unit 202 is a so-called auxiliary memory device, which is composed of a non-volatile memory such as an HDD, an SSD, a ROM, a flash memory, etc. The memory unit 202 stores various data, such as a computer program for controlling the laser processing device 1, various laser parameters input through the input unit 203, and processing graphic data 110 used in welding processing. The control unit 201 loads the computer program stored in the memory unit 202 into the RAM belonging to the working memory and executes the computer program, thereby controlling the first oscillator 2, the second oscillator 3, the hybrid galvanometer scanner 10, the PLC 13, the laser controller 14, etc., and performs the welding process of the workpiece W. In addition, the laser parameters stored in the memory unit 202 are the laser output used in the first oscillator 2 and the second oscillator 3, the processing rate (laser irradiation time), the marking speed, the slow up time, the slow down time, etc.

The input unit 203 includes input devices such as keyboards, mice, and various switches for accepting user operations, and also includes a method of inputting data by connecting to removable recording media such as USB (Universal Serial Bus) memory and SD memory card (secure digital memory card). The data input through the input unit 203 is stored in the memory unit 202. The communication unit 204 communicates with external devices (image processing unit 9, hybrid galvanometer scanner 10, PLC 13, laser controller 14, etc.) connected by wireless or wired communication. The display unit 205 includes a display unit, a video codec, a GPU (Graphics Processing Unit), a memory for image data, etc., which is used to generate a UI (User Interface) screen and display it on the display unit. The user can also input various parameters for instructing the laser controller 14 through the input unit 203 when the UI screen is displayed on the display unit 205.

(7) Overall operation of laser processing Next, the operation of the laser processing device 1 is described with reference to FIG. 15 . First, the workpiece W is placed on the workpiece setting table 11 (step S11). The control personal computer 12 sets the laser parameters (laser output, deceleration time, deceleration time, etc.) for the first oscillator 2 and the second oscillator 3 via the laser controller 14 (step S12). The user operates the input unit 203 of the control personal computer 12 to input the processing graphic data 110, and the control personal computer 12 logs the processing graphic data 110 into the memory unit 202 (step S13). FIG. 16 shows a login screen 150 as an example of a UI screen when the user inputs the laser parameters and processing graphic data. The login screen 150 is a UI screen for logging in the laser parameters used in the first oscillator 2 and the second oscillator 3 and the processing graphic data used in the hybrid galvanometer scanner 10 during the laser irradiation in the third step described later.

As an example, the login screen 150 includes a job list 151, a processing point list 152, a processing image 153, a laser parameter input unit 154, and a login button 155. For example, when "straight line" is selected in the job list 151 and the xy coordinate value of the processing point is added in the processing point list 152, a graphic connecting each processing point with a straight line is displayed in the processing image 153. When the user selects the login button 155 in this state, the processing graphic data 110 displayed in the processing image 153 is registered in the memory unit 102. In addition, the so-called processing graphic data 110 is the information required for the hybrid galvanometer scanner 10 to scan the laser light according to the processing image 153. Here, in this embodiment, two flat wires 52 with a gap and position deviation are subjected to laser irradiation in three steps consisting of a first step, a second step, and a third step, thereby performing a welding process.

The processing of step S11, step S12 and step S13 does not necessarily need to be performed in this order. The workpiece setting table 11 carrying the workpiece W is moved so that the workpiece W is arranged directly below the image processing unit 9 (step S14). Then, the image processing unit 9 takes an image of the workpiece W (step S13). Specifically, the lighting device 101 projects a plurality of stripe patterns (strip patterns) onto the workpiece W from a plurality of different directions by a pattern projection method, and each image is taken by the shooting device 102, and the controller 103 synthesizes each of the taken images and calculates a three-dimensional shape (step S14).

Next, the controller 103 of the image processing unit 9 performs the measurement processing of the center position and height of each flat wire 52 (step S17), and generates CSV data (coordinate table 113) recording the measurement results. The image processing unit 9 sends the CSV data (coordinate table 113) recording the measurement results to the control personal computer 12 (step S18). The CSV data can be sent from the image processing unit 9 to the control personal computer 12 via a wireless or wired network, or via a removable recording medium such as a USB memory or an SD memory card.

Next, the control personal computer 12 performs laser processing (step S19). In the present embodiment, it is assumed that the scanning movable range of the hybrid galvanometer scanner 10 covers the entire size of the workpiece W. However, in the case of welding processing of a motor larger than the scanning operation range of the galvanometer scanning, the laser processing device 1 can also perform welding processing while rotating the workpiece W by the θ-axis table 11θ of the workpiece setting table 11. Depending on the size of the motor, there is a method of performing welding processing while rotating a quarter of the motor at a time, and there is also a method of performing welding processing while rotating a eighth of the motor at a time.

(8) Measurement Processing Operation Here, the measurement processing operation performed by the image processing unit 9 as a preliminary preparation for welding processing is described. FIG. 17 and FIG. 18 are flowcharts showing the measurement processing operation performed by the image processing unit 9 and are detailed descriptions of step S17 in FIG. 15 . In practice, the measurement processing operation is performed by the processor 105 executing the measurement program 111 stored in the memory 104 of the controller 103. The image processing unit 9 repeats steps S21 to S36 for each measurement range of the workpiece W. In this embodiment, as an example of a measurement range, as shown in FIG. 19 , a plurality of flat wires 52 (four flat wires 52 in this example) arranged in the radial direction of the stator 50 are used as one measurement range.

The image processing unit 9 performs the first binary large object analysis process (step S22). Binary large object analysis is a type of image analysis, which is used to perform a binarization process on each pixel contained in the target image data, and use the binarized image data to perform various analyses and measurements. As shown in FIG20, the first binary large object analysis process is to perform a binarization process on the cross-sectional shape of the flat wire 52 contained in the measurement range when the xy plane 57 is cut. The xy plane 57 can be set to an arbitrary height, but since the laser irradiation is performed toward the end face of the flat wire 52, it is necessary to set the xy plane 57 to at least the front end side where the insulating coating film 58 has been peeled off. Next, the image processing unit 9 labels (numbers) the flat wire 52 as shown in FIG19. As an example, the arrangement is labeled in a clockwise direction from 0 degrees. In addition, in the radial direction, the labels are labeled in order from the center of the stator 50 toward the outside. Here, as an example, a pair of flat wires 52 belonging to the welding object are labeled with a common value. The pair of flat wires 52 labeled with a common value is labeled "A" for the inner side in the radial direction and "B" for the outer side in the radial direction.

(a) in FIG. 21 shows the image data 120a after the measurement range has been binarized. The image data after the binarization is actually represented by two color levels, white and black, but for the convenience of explanation, the black color is indicated by a hatching pattern in this embodiment. The following processing is described with reference to (a) to (c) in FIG. 21. The image data 120a includes a binary large object (blob) B21, a binary large object B22, and a binary large object B23. The controller 103 of the image processing unit 9 repeats steps S24 to S33 for each binary large object contained in the image data 120a. First, the controller 103 measures the center coordinates (x, y) of the binary large object (step S25), and further measures the area (step S26). Then, the measured area is compared with the pre-stored threshold value 112. In this way, it is determined whether the flat wires are connected to each other. The threshold value 112 can be set according to the cross-sectional area of the flat wire 52, and as an example, it is set to more than 1.5 times and less than 2.0 times the cross-sectional area.

In addition, in the present embodiment, the threshold value may also be a value that can be overwritten. It may also be overwritten in response to the properties such as the shape or material of the measured object, or a predetermined physical quantity or value. In the case where the area of the binary large object is below the threshold value (no in step S27), the process proceeds to step S32. In the case where the area of the binary large object is larger than the threshold value (yes in step S27), a mask area is arranged on the binary large object that is the object, and the binary large object is divided (step S28). For example, in the case of dividing the binary large object B23 (the center position is represented by the component symbol P23) shown in (a) of FIG. 21, a mask area of a thin and long shape including the center position P23 is arranged on the image data as shown in (b) of FIG. 21. The mask area is an area that is not identified in image processing. In this embodiment, the image processing calculates the spacing, step difference, position deviation, etc., and the laser irradiation is performed in consideration of these spacing, step difference, position deviation, etc., but the arrangement of each flat line 52 itself is pre-positioned. Therefore, the controller 103 calculates and configures the position of the mask area in response to the position of the flat line 52 corresponding to the large binary object being the object. In addition, the line width of the mask area only needs to be about one pixel to two pixels. (b) in Figure 21 shows the image data 120b after the mask area is configured.

Next, the controller 103 performs a second binary large object analysis process on the image data 120b (step S29). As a result, in the image data 120c of (c) in FIG. 21 , the binary large object B23 is divided into a binary large object B24 and a binary large object B25. The controller 103 labels the divided binary large objects (step S30). Thus, all flat lines 52 can be identified by numerical values from 1 to 48 and symbols A and B. Furthermore, the controller 103 determines the center coordinates of the binary large objects B23 and B24 (step S31). Next, the controller 103 measures the average height of the flat wire 52 for an arbitrary range including the center position obtained as a result of the binary large object analysis processing (step S32). In the present embodiment, as an example, as shown in FIG22, the average height is measured for a circle (R21, R22, R23) with the center position (P21, P22, P23) of each flat wire 52 as the center. The measured average height is used as the height (z) of the flat wire 52. The controller 103 can also measure the height for a point at the center position of each flat wire 52, and can also calculate the average height for a predetermined range as shown in FIG22 to absorb the measurement error.

Next, the controller 103 calculates the coordinate value (x, y, z, θ) of the middle point of the two corresponding flat lines 52 (step S34). Furthermore, in the case where there is a step difference between the two corresponding flat lines 52, the controller 103 calculates the z-axis offset value (step S35). The offset value will be described later. When the controller 103 completes the measurement of the center position and height (x, y, z, θ) and the coordinate value and height (x, y, z, θ) of the middle point for all flat lines 52, a coordinate table 113 recording the measurement results is generated (step S37). Specifically, the generated coordinate table 113 is CSV data. Figure 21 is a diagram showing the data structure of the coordinate table 113.

Thus, even in the case where the controller 103 performs two binary large object analysis processes to make the flat wires contact each other, the center position of each flat wire 52 can be accurately measured. (9) Laser processing Here, the laser processing of the present embodiment is described in detail. (9-1) Three basic steps First, the three basic steps of welding performed by the laser processing device 1 are described. A welding method is provided, in which, in the butt welding of flat wires performed by the laser processing device 1 of the present embodiment, even if a gap is left, laser leakage does not occur from the gap, and good welding quality and welding strength can be maintained and the processing time can be shortened. Specifically, the laser processing device 1 performs a welding method consisting of three steps: a first step, a second step, and a third step.

FIG24 is used to illustrate the welding method consisting of three steps. Here, as an example, the following situation is used as an example: when two flat wires 52 with end faces of 2.0 mm × 2.5 mm are butted, a gap 53 of 0.5 mm is left. In addition, when the focusing diameter of the first laser light L1 is d1 and the focusing diameter of the second laser light L2 is d2, d1 = 1050 μm, d2 = 40 μm. (a) in FIG24 shows the trajectory I1 of the irradiation of the first laser light L1 and the second laser light L2 in the first step. In the first step, the end surface 52a of the flat wire 52 on the left side of the figure is reciprocated in a substantially straight line in the y-axis direction at a position 1.0 mm away from the center O of the workpiece W in the x-axis direction (the center O is the center of the workpiece W including the gap 53). The irradiation width of the reciprocating irradiation is 1.0 mm in the y-axis direction. In the first step, the first laser light L1 and the second laser light L2 are irradiated at a speed of 500 mm/s.

(b) in FIG. 24 shows the irradiation trajectory I2 of the first laser light L1 and the second laser light L2 in the second step. In the second step, the end face 52a of the flat wire 52 on the right side of the figure is reciprocated in a substantially straight line in the y-axis direction at a position 1.0 mm away from the center O of the workpiece W in the x-axis direction. The irradiation width of the reciprocating irradiation is 1.0 mm in the y-axis direction. Similar to the first step, the first laser light L1 and the second laser light L2 are irradiated at a speed of 500 mm/s in the second step. (c) in FIG. 24 shows the irradiation trajectory I3 of the first laser light L1 and the second laser light L2 in the third step. The track I3 is an ellipse with a short diameter of 1.2 mm and a long diameter of 2.4 mm; in the third step, the elliptical circular irradiation is performed across the left and right flat conductors 52. In the third step, the first laser light L1 and the second laser light L2 are irradiated at a speed of 1000 mm/s.

In each of the first step, the second step, and the third step, when a rapid temperature rise occurs at the weld surface, sputtering occurs. Therefore, the second laser light L2 with a high power density can also be controlled in the following manner: irradiation starts at a low output and the power is gradually increased until the specified output is reached. In the present embodiment, the second laser light L2 can also be controlled in the following manner in each step: it takes 5.0 ms to increase the output from 0 to 1.5 kW. Figure 25 is used to illustrate the changes in the weld surface caused by welding in three steps in this way. Figure 25 is a schematic diagram schematically showing the changes in the weld surface. Here, for the convenience of explanation, the flat line 52 on the left side of the figure is recorded as "A", and the flat line 52 on the right side of the figure is recorded as "B".

(a) The first step of irradiation is started for the flat wire A, and the end face 52a is melted. (b) The corner of the end face 52a of the flat wire A is melted and has an arc shape, thereby forming a first molten portion 54. The laser processing device 1 performs the first step of irradiation (for example, irradiation is stopped after 68 milliseconds) until the shoulder of the first molten portion 54 sags. Here, the so-called "shoulder sag" refers to a state in which a part of the first molten portion 54 formed on the end face 52a enters the gap 53 and begins to flow down. (c) Then, the second step of irradiation is started for the flat wire B, and the end face 52a of the flat wire B is melted. (d) The corner of the end face 52a of the flat wire B is melted and has an arc shape, thereby forming a second molten portion 55. The laser processing device 1 performs the second step of irradiation (for example, irradiation is stopped after 68 milliseconds) until the shoulder of the second molten portion 55 sags.

(e) The first melting part 54 and the second melting part 55 are connected. Here, since the timing of laser irradiation of the flat wire A and the flat wire B is different, there is a possibility that the molten metal of the flat wire A is cooled and solidified at the time point of the second step irradiation. (f) Therefore, after the first melting part 54 and the second melting part 55 are connected, the third step irradiation is performed to give heat energy to the flat wire A again, thereby making the first melting part 54 and the second melting part 55 uniform and forming a melting part 56. The irradiation of the third step can also be continued until the melting part 56 becomes the desired size (as an example, the irradiation is stopped after 70 milliseconds). Here, as shown in Figures 24 and 25, in the first step and the second step, it is desired to irradiate the laser light at a position deviated from the center of each end face 52a, that is, it is desired to irradiate the laser light at a position closer to the butt surface than the center (a position close to the gap 53). This can shorten the time until the molten parts are connected. Then, the third step is performed after the two molten parts are connected, thereby preventing the laser from leaking from the gap 53 and causing damage to the lower part of the flat wire. In addition, the molten parts that have been connected in the third step are irradiated with laser in a circular manner, thereby making the molten parts uniform and forming a beautiful molten ball that is symmetrical on both sides.

In addition, the irradiation position and irradiation time of each step basically depend on the size of the weld surface. Therefore, the results of the test irradiation, the optimal values of the irradiation position and the irradiation time can be selected for the workpiece with a known position deviation and less step difference, and these optimal values can be stored in the control personal computer 12. Similarly, for the output power of the first laser light L1 and the second laser light L2, the optimal power of each laser can also be stored in the control personal computer 12. In addition, it is also possible to control by the number of irradiations instead of by the irradiation time. In the above description, although the trajectory I3 of the laser irradiation in the third step is elliptical or circular, this is only an example, and the trajectory of the laser irradiation in the third step is not limited to elliptical or circular.

FIG. 26 shows an example of a variation of the trajectory of the laser irradiation in the third step. As shown in the trajectory I7 of (a) in FIG. 26 , the laser processing device 1 may also irradiate the first laser light L1 and the second laser light L2 across two flat lines 52, and irradiate the first laser light L1 and the second laser light L2 in a straight line and back and forth. In addition, as shown in the trajectory I8 of (b) in FIG. 26 , the laser processing device 1 may also irradiate the first laser light L1 and the second laser light L2 in a rectangular shape across two flat lines 52. In addition, as shown in the trajectory I9 of (c) in FIG. 26 , the laser processing device 1 may also irradiate the first laser light L1 and the second laser light L2 in an 8-shape across two flat lines 52. In addition, in addition to straight lines, rectangles, and 8-shapes, polygonal irradiation is also possible.

In particular, when irradiating in a rectangular or figure-8 shape, heat energy is easily transmitted to the end of the workpiece W, thereby promoting the melting of the weld surface (end surface 52). In addition, as shown in (a) of FIG. 27, in the case where the flat wires 52 are normally bonded to each other, even if the laser light is irradiated by elliptical scanning or circular scanning, the laser light will not leak to the bottom; as shown in (b) of FIG. 27, in the case where the melting amount of the end (end surface 52a) of the workpiece W is small, the surface tension also affects, resulting in a state where only the center of the flat wire 52 is bonded. In the case where the area of the bonded portion formed in the gap 53 in this way is small, when the laser light is irradiated by elliptical scanning or circular scanning, the laser light will leak to the bottom. Therefore, when the area of the bonding part is small, the carbonization of the coating and poor insulation caused by laser leakage can be suppressed by 8-shaped laser irradiation or straight line irradiation.

Furthermore, in the laser processing device 1, it is not a necessary configuration to perform the cycloidal irradiation in the third step. As shown in (d) of FIG. 26 , the already joined molten parts can also be irradiated with a fixed point in the third step. The first laser light L1 and the second laser light L2 are irradiated at a fixed point on the center of the workpiece W, whereby heat energy is slowly transferred from the center of the workpiece W toward the end. In this process, the two molten parts can be homogenized. In this way, the third step is sufficient as long as it can achieve the processing of homogenizing at least the molten parts formed by the first step and the second step. (9-2) Action of laser processing Next, the laser processing is described in detail with reference to FIGS. 28 to 33. FIG. 28 is a flow chart showing the action of laser processing. In addition, the actions shown here are the details of step S19 in Figure 15.

The laser processing device 1 repeats the processing from step S41 to step S50 for each pair of flat wires 52 to be welded. The control unit 201 that controls the personal computer 12 refers to the coordinate table 113 to obtain a pair of step difference amounts Δz and spacing amounts Δxy currently being processed (step S42). The control unit 201 refers to the processing rate table 1100 stored in the memory unit 102 to obtain the laser irradiation time corresponding to the step difference amount Δz and spacing amount Δxy obtained in step S42 (step S43). Here, the processing rate table 1100 used in the welding processing of the laser processing device 1 is described. FIG. 29 is a diagram showing the data structure of the processing rate table 1100. The processing rate table 1100 is a table recording the processing rate (laser irradiation time (unit: msec)). The processing rate can be selected according to the step difference Δz in the z direction and the spacing Δxy in the xy plane of a pair of flat wires 52 to be welded.

For example, in the case where the step difference (Δz) is 0.4 mm and the spacing (Δxy) is 0.6 mm, refer to the circled range (field) 1111. Two values are recorded in the circled range 1111. The upper value (76) shows the laser irradiation time of the high flat line 52, and the lower value (58) shows the laser irradiation time of the low flat line 52. As can be seen from FIG. 29, the laser irradiation time of the high flat line 52 is set longer than the laser irradiation time of the low flat line 52. The reason for this is that in order to match the height of the high flat line 52 and the low flat line 52, the melting amount of the high flat line 52 increases. Therefore, in the case of the same spacing amount, the larger the step difference, the longer the laser irradiation time of the high flat line 52. In addition, when the pitch is large, more melting is required to fill the gap, so the larger the pitch, the longer the laser irradiation time.

In this embodiment, the low flat wire 52 is also irradiated with laser light. The irradiation time refers to the state in which the four corners of the end face 52a of the flat wire 52 are melted and part of the molten metal begins to flow down to the gap. This time is a value determined depending on the size of the end face 52a of the flat wire 52, the material composition of the flat wire 52, the power of the first oscillator 2 and the second oscillator 3, the laser wavelength, etc., and the value obtained by test processing can be used. If the size of the end face 52a is different, the irradiation time recorded in the processing rate table will naturally be different. As an example, FIG. 29 shows the irradiation time when the size of the end face 52a is about 2.0mm×2.5mm.

In step S43, the control unit 201 obtains two values recorded in the upper and lower sections of the processing rate table 1100. The value recorded in the upper section is the irradiation time of the first step, and the value recorded in the lower section is the irradiation time of the second step. Here, in the case where the value of the step difference Δz obtained in step S42 is inconsistent with the items (0.0mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm) of the processing rate table 1100, select the item that is closer to the value of the obtained step difference Δz. In addition, in the case where the obtained step difference Δz is an intermediate value, select the item with a value larger than the obtained step difference Δz. For example, in the case where the step difference Δz obtained in step S42 is 0.5mm, the control unit 201 selects the circled range 1112 of the processing rate table 1100. The same applies to the spacing Δxy.

Next, the control unit 201 of the control personal computer 12 determines which flat line is higher in the pair currently being processed (step S44). This determination process is performed by receiving information such as the number for identifying the higher flat line from the controller 103 of the image processing unit 9, but it can also be performed by the control unit 101 reading the coordinate value from the coordinate table 113. The coordinate table 113 can be stored in the image processing unit 9 or in the control personal computer 12. Next, the laser processing device 1 performs the first step (step S45), which is to irradiate the higher pin with the first laser light L1 and the second laser light L2. Specifically, the control unit 201 for controlling the personal computer 12 sends the laser irradiation time obtained in step S43 to the laser controller 14, and sets the laser irradiation time for the first oscillator 2 and the second oscillator 3. Furthermore, the control unit 201 sends a control command to the hybrid galvanometer scanner 10, and the laser irradiation command is sent from the PLC 13 to the first oscillator 2 and the second oscillator 3 via the laser controller 14. The first oscillator 2 and the second oscillator 3 that receive the laser irradiation command irradiate the first laser light L1 and the second laser light L2, respectively.

(a) in FIG. 30, (a) in FIG. 31, and (a) in FIG. 34 are schematic diagrams for explaining the processing of the first step. In addition, in the description of FIG. 30 and FIG. 34, the high flat line 52 is recorded as "B pin" and "52 (B)", and the low flat line 52 is recorded as "A pin" and "52 (A)". The scanning trajectory of the hybrid galvanometer scanner 10 in the first step is a straight line reciprocating irradiation. When the laser light is irradiated at the processing rate (irradiation time) obtained in step S43, the B pin is melted to a height slightly below the A pin, and a molten ball 55b is formed. Here, the first laser light L1 and the second laser light L2 are linearly reciprocating to irradiate the predetermined position of the end surface 52a, but it is preferable to linearly reciprocate to irradiate the position of the end surface 52a close to the butt surface 52b (the position close to the spacing).

Next, the laser processing device 1 performs the second step (step S46), which is to irradiate the low A pin with laser light. (b) in FIG. 30, (b) in FIG. 31, and (b) in FIG. 34 are schematic diagrams for illustrating the processing of the second step. In the second step, the first laser light L1 and the second laser light L2 are irradiated to the welding surface of the A pin. At this time, the scanning trajectory of the hybrid galvanometer scanner 10 is a straight reciprocating irradiation like the first step. When the laser light is irradiated at the processing rate (irradiation time) obtained in step S43, the entire end face 52a of the A pin is melted and a molten ball 55a is formed on the A pin. As shown in (b) of FIG. 34 , due to the difference in laser irradiation time, the molten ball 55a is smaller than the molten ball 55b.

In addition, similar to the first step, the second step can also linearly reciprocate to irradiate the position of the end face 52a close to the butt surface 52b (the position close to the spacing). In this way, the laser light is irradiated close to the inner side, thereby shortening the time until the molten part (molten ball 55a and molten ball 55b) is combined. Then, the control unit 201 that controls the personal computer 12 corrects the processing graphic data 1100 stored in the memory unit 202 according to the configuration of the A pin and the B pin (step S47). (a) in Figure 32 is a processing image displayed by the processing graphic data 1100 stored in the memory unit 102, and is an 8-shaped shape. The 8-shaped shape is based on the origin (0,0) of the xy orthogonal coordinate system as the center e and connects point a, point b, point c, and point d. (b) in FIG. 32 is a processing image displayed by correcting the processing graphic data 1100 according to the actual configuration of the A pin and the B pin.

A method for correcting the processing graphic data 1100 is described. The control unit 201 that controls the personal computer 12 makes the center e of the processing graphic data 1100 consistent with the AB pin coordinates. In addition, the processing graphic data 1100 is rotated and stretched in the x-axis direction in such a manner that the midpoint of the straight line connecting the points a and d of the processing graphic data 1100 is consistent with the coordinates of the A pin and the midpoint of the straight line connecting the points c and b of the processing graphic data 1100 is consistent with the coordinates of the B pin. In this way, the corrected processing graphic data is in the shape of a figure 8, and the figure 8 shape is centered on the AB pin coordinates e and connects the points a', b', c', and d'. The control unit 201 sends the corrected processing graphic data to the hybrid galvanometer scanner 10.

Next, before the third step, the focus position of the laser processing device 1 is shifted to the height of the B pin before melting (step S48). Then, after the two molten balls 55a and 55b are combined, the laser processing device 1 uses the corrected processing graphic data to perform the third step (step S48), and the third process (step S48) is to irradiate the first laser light L1 and the second laser light L2 across the A pin and the B pin. In the third step, the irradiation is performed in a circular shape, a circle, or an 8-shaped shape across the A pin and the B pin. The laser processing device 1 applies heat energy to the A pin and the B pin again in the third step, thereby homogenizing the molten part and forming a beautiful molten ball that is symmetrical on both sides. The third step can also be continued until the molten ball becomes the desired size.

In this way, after the two molten balls 55a and 55b are combined, the third step is performed to prevent the laser light from leaking from the gap and causing damage to the lower part of the flat wire. In addition, as shown in (c) in Figure 34, pin A and pin B are combined with a molten ball 55. However, when the energy of the irradiated laser light is strong, there is a possibility that the laser light penetrates the molten ball 55 and causes damage to the lower part of the flat wire. Therefore, in the third step, the focal position of the laser light is offset upward to reduce the energy density of the laser light irradiated to the molten ball 55. In this way, the laser light is prevented from penetrating the molten ball 55. The offset value uses the value recorded in the coordinate table 113. As an example, the laser processing device 1 uses the z-axis stage 11z to offset the position of the hybrid galvanometer scanner 10 to the height of the higher pin before welding.

When the laser processing device 1 completes the welding process of all the pairs of flat wires contained in the workpiece W, the welding process of the workpiece W is completed. As a variation example of the third step, FIG. 33 is used for explanation. (a) in FIG. 33 shows the scanning trajectory of the third step in the case where there is a gap in the x-axis direction. (b) in FIG. 33 shows the scanning trajectory of the third step in the case where there is a positional deviation in the y-axis direction. In all cases, the center point of the registered processing graphic data 1100 (8-shaped) is matched with the AB pin coordinates and the processing graphic data 1100 is further rotated and/or stretched by the A pin coordinates and the B pin coordinates. This allows laser light to be irradiated with a scanning trajectory corresponding to the configuration of various A pins and B pins.

In addition, although the laser scanning trajectory of the third step is in the shape of an 8, this is only an example and is not limited to the shape of an 8. The third step is sufficient as long as the following processing can be achieved: when the molten parts of the A pin and the B pin formed in at least the first step and the second step are combined, the molten parts are stirred and homogenized by passing through the scanning trajectory near the center of the combined molten parts. For example, as shown in (c), (d), and (e) in Figure 33, the scanning trajectory of the third step can also be a straight line reciprocating irradiation across the A pin and the B pin. In this case, the processing graphic data showing the straight line is pre-registered in the memory unit 202 of the control personal computer 12, and the control unit 201 corrects the registered processing graphic data according to the configuration conditions of each pair. Specifically, the straight line is rotated in the θ direction and stretched in the x-axis direction in such a way that the center point of the straight line matches the AB pin coordinates and the starting point and end point of the straight line match the A pin coordinates and the B pin coordinates. In this way, reciprocating straight line irradiation corresponding to various pair configuration conditions can be achieved.

In the case where a pair of flat wires 52 is spaced apart or deviated in position in the x-axis direction, the y-axis direction, or the θ rotation direction, it is assumed that the area of the molten portion connected by the irradiation of the first step and the second step becomes smaller. Even in the case where the area of the molten portion becomes smaller, the laser light is irradiated with a scanning track passing through the center of the molten portion to suppress the leakage of the laser light from the gap. In this way, it is possible to suppress the carbonization and poor insulation caused by irradiating the coating portion at the bottom of the flat conductor with laser light.

(10) Effect of the Implementation Form The laser processing device 1 irradiates the first laser light L1 with a wavelength of 300nm to 600nm and a high light absorption rate relative to copper at high speed, thereby forming a molten pool on the workpiece W. Then, the second laser light L2 with a small focusing diameter and high energy density is irradiated inside the formed molten pool, thereby achieving a local deeper melting depth inside the molten pool, thereby promoting the formation of the molten pool. In addition, compared with the previous welding device, the laser processing device 1 uses the first laser light L1 with a large focusing diameter for welding, thereby effectively giving heat energy to the workpiece W and melting the workpiece W.

In addition, the laser processing device 1 does not irradiate the first laser light L1 and the second laser light L2 at a fixed point, but scans and irradiates the first laser light L1 and the second laser light L2 at a high speed, thereby generating flow in the molten pool. In this way, the generated bubbles are discharged from the molten pool that has reached a high temperature to the outside. In this way, porosity can be suppressed. Furthermore, it is possible to prevent the local concentration of heat energy in the molten pool, thereby stabilizing the molten pool and reducing spattering. Since porosity and spattering are the main factors of welding defects such as poor bonding, the laser processing device 1 of this embodiment and the welding method using the laser processing device 1 can suppress the occurrence of welding defects. In addition, as described above, it is possible to suppress the laser leakage from the gap 53 generated when the flat wires are butted together, thereby suppressing the carbonization of the coating and poor insulation that are associated with the laser leakage.

The laser processing device 1 melts the higher flat wire in the first step and then melts the lower flat wire in the second step when the front ends of two flat wires with a step difference are butt-jointed. At this time, the melting amount in the first step is set to be larger than the melting amount in the second step. In this way, it is possible to suppress the occurrence of spattering after the step difference is eliminated. Assuming that the melting amount in the first step and the melting amount in the second step are set to be equal (for example, in the case where the two molten balls are melted to the extent of being combined in the minimum time), a tilted molten ball 55c is formed as shown in (d) in FIG. 34. In this way, both the welding quality and the welding strength are insufficient. On the other hand, the laser processing device 1 of this embodiment sets the melting amount of the first step to be greater than the melting amount of the second step, thereby forming a molten ball 55 that is evenly distributed on the left and right as shown in (c) of Figure 34, thereby improving the welding quality and welding strength.

In addition, the laser processing device 1 includes an image processing unit 9, which obtains the position information (coordinate value) of each pin included in the stator 50, and uses the obtained position information to adjust the laser irradiation position. In particular, the laser processing device 1 irradiates the laser light with a scanning trajectory passing through the center coordinates of the AB pins in the processing of the third step, thereby suppressing the laser light from leaking to the lower part of the flat wire from the position where the spacing and position are deviated. In this way, the carbonization of the coating can be suppressed, and the welding quality and welding strength can be ensured.

[Implementation Form 2] Next, the laser processing device of Implementation Form 2 is described. In the above-mentioned Implementation Form 1, the height of each flat conductor used to constitute the segmented coil in the workpiece W to be welded is slightly uniform in the entire motor. However, there may be a case where, depending on the type of motor, there is a flat conductor with a higher height for connecting to the wire near the flat conductor used to constitute the segmented coil. When a high flat conductor stands vertically near the flat conductor to be welded, in the case where a molten ball is formed on the end surface of the flat conductor to be welded, there may be a case where the molten ball reflects the laser light, causing the reflected light of the laser light to irradiate the coated part of the high flat conductor. In this way, there is a possibility that the coated part is damaged by heat energy and becomes unusable.

Therefore, the laser processing device of the second embodiment provides a method for manufacturing a stator. Even when a high flat conductor stands vertically near a flat conductor to be welded, in order to suppress the problem that the coated portion of the high flat conductor is damaged by heat energy and becomes unusable, welding processing is performed with an appropriate welding pattern according to the peripheral condition of the flat conductor to be welded. (1) Configuration of laser processing device As in the embodiment, the laser processing device of the second embodiment is a welding device that irradiates a workpiece W with laser light and converts the energy of the laser light into heat to weld the workpiece W. The overall configuration of the system is the same as the laser processing device 1 shown in Figures 1 and 2.

Here, the control personal computer 22 which is different from the first embodiment is mainly used for explanation. As shown in FIG. 38 , the control personal computer 22 is composed of a control unit 201, a memory unit 202, an input unit 203, a communication unit 204, and a display unit 205. The memory unit 202 stores computer programs and various data for controlling the laser processing device. In particular, the memory unit 202 holds the characteristic drawing pattern 121 and the pattern table 122 of the present embodiment, and these drawing patterns 121 and the pattern table 122 are data used for the welding process of the workpiece W. The details will be described later. The processing unit 211 of the control unit 201 loads the computer program stored in the memory unit 202 into the RAM belonging to the working memory and executes the computer program, thereby controlling the first oscillator 2, the second oscillator 3, the hybrid galvanometer scanner 10, the PLC 13, the laser controller 14, etc., to perform the welding process of the workpiece W.

(2) Regarding the workpiece W Next, the stator 50 belonging to the workpiece W is described using FIG. 39 (a) is a perspective view showing the schematic structure of the stator 50 belonging to the stator of the motor of an electric vehicle, etc. As shown in FIG. 39 (a), the stator 50 is composed of the following components: a stator core 51 having a substantially cylindrical shape, having a plurality of grooves 54 arranged in the circumferential direction; a plurality of flat conductors 52, which are inserted into the grooves 54 and form segmented coils; and a plurality of flat conductors 60, which are inserted into the grooves 54 and are used for conducting electricity with the outside.

The flat conductor 52 and the flat conductor 60 are electric wires having a rectangular cross section, that is, flat wires. The flat conductor 52 and the flat conductor 60 are generally made of pure copper, but may also be made of a metal material having a high electrical conductivity, such as an alloy with copper as a main component, an alloy composed of copper and aluminum, etc. The ends of the flat conductor 52 and the flat conductor 60 protrude from the upper end of the stator core 51, but the protrusion of the flat conductor 60 is greater than that of the flat conductor 52, that is, the height of the flat conductor 60 is higher than that of the flat conductor 52. Although the flat conductor 52 and the flat conductor 60 are covered with an insulating film, the insulating film at the end of each of the flat conductor 52 and the flat conductor 60 is peeled off for electrical connection.

FIG. 39( b) is an enlarged view for explaining an example of the arrangement of the flat conductor 52 and the flat conductor 60. In this example, the two flat conductors 52 to be welded are arranged to be sandwiched by the two flat conductors 60. The laser processing device irradiates the end faces 52a of the two flat conductors 52 with the end faces 52a butted against each other to perform welding processing. At this time, as shown in FIG. 39( b), when the high flat conductor 60 approaches the flat conductor 52 to be welded, a problem caused by reflected light occurs as follows.

That is, as shown in FIG40, when two flat conductors 52 are welded while the hybrid galvanometer scanner 10 scans the first laser light L1 and the second laser light L2, a hemispherical molten ball 55 is formed on the welded surface (the area where the two end faces 52a are aligned). After the molten ball 55 is formed until the welding process is completed, the first laser light L1 and the second laser light L2 are reflected by the molten ball 55. When the reflected light L3 of the molten ball 55 is irradiated to the adjacent flat conductor 60, there is a possibility that the coated portion is carbonized, making the flat conductor 60 unusable. In view of this problem, the laser processing device focuses on the scanning trajectory of the laser light, that is, the drawing pattern of the hybrid galvanometer scanner 10, and performs welding processing while suppressing the reflected light L3 caused by the molten ball 55 from irradiating the adjacent flat conductor 60.

In addition, of the first laser light L1 and the second laser light L2 irradiated to the molten ball 55, the laser light that causes damage to the coating by reflected light is mainly the second laser light L2 (IR (infrared) laser). The absorption rate of IR laser is a low value of about 6% relative to copper, and the remaining about 94% is not absorbed but reflected. In addition, although the second laser light L2 reflected by the molten ball 55 will diffuse, the fiber laser has the characteristics of high beam quality and difficulty in diffusion, and it is easy to cause damage to the coating due to reflection. On the other hand, since the first laser light L1 (blue laser) has a high absorption rate relative to copper, its reflectivity is low. In addition, since the first laser light L1 used in the present embodiment has low output and diffuses widely after reflection, the damage caused by the reflection of the first laser light L1 is relatively small due to the very low power density of the reflected light.

(3) Setting and drawing patterns for prohibited irradiation areas Here, the drawing patterns used in the welding process of this embodiment are described. First, the prohibited irradiation area is described using FIG. 41. The area affected by the molten ball 55 depends on the distance between the flat conductor 52 to be welded and the adjacent flat conductor 60, the size of the flat conductor 60, the size of the molten ball 55, the curved surface shape of the molten ball 55, etc. However, the molten ball 55 grows as the irradiation time passes, and the size of the molten ball 55 is not fixed. Furthermore, the molten ball 55 is kept in a raised state on the welding surface by surface tension, while being stirred and shaken by laser irradiation. Therefore, the shape during processing is also not fixed.

Therefore, in the present embodiment, as shown in FIG. 41, based on the distance between the flat conductor 52 to be welded and the adjacent flat conductor 60, the size of the flat conductor 60, and the size of the weld surface (the area where the two end surfaces 52a have been matched), the area shown by the diagonal line in the figure is specified in the prohibited irradiation area. The prohibited irradiation area is the area where the reflected light L3 will hit the adjacent flat conductor 60 when the laser light passes through. Therefore, when the laser light is irradiated with a pattern such that the laser light does not pass through the prohibited irradiation area on the weld surface, the reflected light L3 will not irradiate the flat conductor 60. In addition, the prohibited irradiation area can also be specified using at least one of the distance between the flat conductor 52 and the adjacent flat conductor 60, the size of the flat conductor 60, the size of the molten ball 55, the curved surface shape of the molten ball 55, and the area of the end surface 52a.

The laser processing device of this embodiment performs welding processing while switching the depiction pattern in response to the peripheral conditions of the flat conductor 52 to be welded. That is, in the case where the flat conductor 52 to be welded is adjacent to the flat conductor 60, welding processing is performed with such a depiction pattern that does not pass through the prohibited irradiation area; in the case where the flat conductor 52 to be welded is not adjacent to the flat conductor 60, welding processing is performed with the depiction pattern with the best time efficiency, thereby shortening the tact time of the stator 50 as a whole. The depiction pattern 121 stored in the memory unit 202 is composed of a plurality of depiction patterns, as an example, including pattern A, pattern B and pattern C as shown in FIG. 42. The drawing pattern 121 can be input by the user operating the input unit 203 while displaying a UI screen for inputting the drawing pattern to the display unit 205; the drawing pattern 121 can also read information stored in a removable recording medium and store it in the storage unit 202.

The pattern A shown in (a) of FIG. 42 is a depiction pattern, which is used when the two flat conductors 52 to be welded are not adjacent to the flat conductor 60. In the pattern A, as shown in the trajectory I1, the first laser light L1 and the second laser light L2 are irradiated in a predetermined rotation diameter across the two flat conductors 52. The rotation irradiation of the pattern A has a high melting efficiency, and can be welded more quickly than the patterns B and C described later. The pattern B shown in (b) of FIG. 42 is a depiction pattern, which is used when the flat conductor 52 to be welded is adjacent to the flat conductor 60. In the pattern B, as shown in the trajectory I2, the first laser light L1 and the second laser light L2 are irradiated in an 8-shaped trajectory that does not pass through the prohibited irradiation area.

Pattern C shown in (c) of FIG. 42 is a variation of pattern B. It is a drawing pattern like pattern B and is used in the case where a flat conductor 52 to be welded is adjacent to a flat conductor 60. Pattern C is a trajectory I3 in which the first laser light L1 and the second laser light L2 are reciprocatedly irradiated in an inclined direction that does not pass through the prohibited irradiation area. Since pattern C is a trajectory connecting two points, it is a trajectory that is easy to correspond to the peripheral conditions of the molten portion. In addition, since it is a straight line pattern, it has the advantage of low difficulty in generating the drawing pattern. On the other hand, since melting takes time, it is expected that the production distance time will be extended. In addition, there is a possibility that the left and right balance of the molten ball 55 formed on the weld surface will deteriorate.

The laser processing device performs welding processing of the workpiece W while switching between pattern A and pattern B (pattern C can also be used instead of pattern B), and at this time, the pattern table 122 stored in the memory unit 202 is used. Here, Figures 43 and 44 are used to illustrate the pattern table 122. Figure 43 is a stator that briefly shows an example of the workpiece W. The two white rectangles in a pair show the flat conductor 52 that is the object of welding, and the black rectangle shows the flat conductor 60 that is the high pin. The table that records what kind of pattern is used to weld the flat conductor 52 that is the object of welding is the pattern table 122 shown in Figure 44.

The pattern table 122 corresponds to the workpiece W one-to-one, and records the depicted pattern corresponding to the arrangement of the flat conductors of the workpiece W. The pattern table 122 is stored in the memory unit 102 before the welding process. Similar to the depicted pattern 121, the user can also operate the input unit 203 to input when the display unit 205 displays a UI screen for inputting the pattern table 122, or read the information stored in the recording medium and store it in the memory unit 202, or receive it via the network and store it in the memory unit 202. The pin number is used as the position information for indicating the position of the flat conductor 52 that is the welding object. As shown in FIG. 43, the pin number is a combination of letters arranged in the circumferential direction of the stator and numbers arranged in the radial direction of the stator. As shown in FIG. 44, the pattern table 122 records the pin numbers and the depicted patterns in correspondence.

In the present embodiment, pattern B is used when the flat conductor 52 to be welded is adjacent to one or more high flat conductors 60, and pattern A is used in other cases. Specifically, a pair of flat conductors 52 identified by pin number "A-1" is adjacent to two flat conductors 60, and is welded using pattern B. A pair of flat conductors 52 identified by pin number "A-2" is adjacent to one flat conductor 60, and is welded using pattern B. Since a pair of flat conductors 52 identified by pin number "A-3" is not adjacent to a flat conductor 60, pattern A is used for welding. (3) Operation of laser processing device 1 Here, the operation of the laser processing device 1 of the present embodiment is explained using the flowchart of FIG. 45. First, start with the workpiece W already set on the workpiece setting table 11.

The pattern table corresponding to the workpiece W set on the workpiece setting table 22 is input through the input unit 203 of the control personal computer 22 (step S51). Then, the drawing pattern (pattern A, pattern B, etc.) required for the welding process of the workpiece W is input through the input unit 203 of the control personal computer 22 (step S52). The order of step S51 and step S52 can also be reversed. Then, various parameters of the first oscillator 2 and the second oscillator 3 are sent from the control personal computer 22 to the laser controller 14, and the laser controller 14 sets the parameters for each oscillator (step S53). In addition, the drawing pattern (pattern A, pattern B, etc.) used in the welding process is transferred from the control personal computer 22 to the hybrid galvanometer scanner 10.

Next, the workpiece setting table 11 is moved in such a manner that the hybrid galvanometer scanner 10 and the center of the coverage range of the hybrid galvanometer scanner 10 in the workpiece W are opposite to each other, thereby moving the workpiece W (step S54). Next, the irradiation position of the hybrid galvanometer scanner 10 is aligned with the flat conductor 52 recorded in the first row of the pattern table. The steps so far are the previous preparations for the welding process, and the welding process of the workpiece W is started below. The processing unit 211 of the control personal computer 22 refers to the pattern table stored in the memory unit 202 to determine whether the depicted pattern corresponding to the flat conductor 52 currently being the welding object is pattern A or pattern B (step S56). The processing control unit 211 sends a processing action instruction to the hybrid galvanometer scanner 10, and the processing action instruction includes information for identifying the processing pattern that has been judged.

In the case of pattern A, that is, in the case where there is no high flat conductor 60 adjacent to the flat conductor 52, the hybrid oscillator scanner 10 that has received the processing action instruction selects pattern A (step S57). In the case of pattern B, that is, in the case where there is a high flat conductor 60 adjacent to the flat conductor 52, the hybrid oscillator scanner 10 selects pattern B (step S58). Afterwards, a laser irradiation instruction is sent from PLC13 to the first oscillator 2 and the second oscillator 3. The first oscillator 2 and the second oscillator 3 that have received the laser irradiation instruction irradiate the first laser light L1 and the second laser light L2 respectively (step S59). As described in the first embodiment, the laser irradiation of step S59 is a three-step laser irradiation consisting of the first step, the second step, and the third step. That is, the laser irradiation of step S59 can also be controlled as described in the first embodiment according to the configuration conditions (spacing, position deviation, step difference, etc.) of a pair of flat conductors 52 to be welded.

The hybrid galvanometer scanner 10 matches the irradiation position to the flat conductor 52 that is the next welding object (step S60). In this embodiment, it is assumed that the range of motion of the hybrid galvanometer scanner 10 is about one-fourth of the size of the workpiece W. Therefore, the laser processing device performs the welding process of the entire workpiece W while rotating the workpiece W by one-fourth each time by the θ-axis table 11θ. After step S60, the processing unit 211 determines whether one-fourth of the workpiece W has been processed (step S61). If one-fourth of the processing has not been completed (no in step S61), return to step S55 and continue processing.

When the processing of one quarter of the workpiece W is completed (yes in step S61), the processing unit 211 determines whether the overall processing has been completed (step S62). When the overall processing of the workpiece W is not completed (no in step S62), the processing unit 211 instructs the θ-axis table 11θ to rotate the workpiece W by one quarter through PLC13. The θ-axis table 11θ drives the rotating mechanism and rotates the table by one quarter (step S63). After that, it returns to step S55 and continues processing. When the overall processing of the workpiece W is completed (yes in step S62), the laser processing device ends the welding processing of the workpiece W.

(4) Effect of the second embodiment As described above, the laser processing device of this embodiment switches the drawing pattern while performing the welding process of the stator 50 as a whole according to the situation near the flat conductor 52 to be welded. Specifically, when there is a flat conductor 60 with a high pin nearby, the laser light is irradiated with a drawing pattern that will not be affected by the reflected light caused by the molten ball; when there is no flat conductor 60 nearby, the laser light is irradiated with a drawing pattern with the highest melting efficiency. In this way, it is possible to avoid damage caused by reflected light and shorten the production time.

Furthermore, in the case where the workpiece W is changed to a stator having a pin arrangement different from that of the stator 50, it is sufficient to input the pattern table and the drawing pattern corresponding to the changed stator into the control personal computer 11. In this way, regardless of the stator having any pin arrangement, damage caused by reflected light can be avoided and the production time can be shortened. (5) Variation In the above-mentioned second embodiment, an embodiment is described in which the drawing pattern and the pattern table corresponding to the pin arrangement of the workpiece W are stored in the memory unit 202 in advance via the input unit 203 of the control personal computer 22.

Here, the following variation is described: the image processing unit 9 analyzes the pin arrangement of the workpiece W and generates a drawing pattern and a pattern table. As described in the first embodiment, the image processing unit 9 has the following functions: photographing the workpiece W placed on the workpiece setting table 11 and analyzing the pin arrangement of the workpiece W. That is, the image processing unit 9 can determine whether a high flat conductor 60 is adjacent to the flat conductor 52 that is the welding object. The image processing unit 9 sends the analysis result to the control personal computer 22. Figure 46 is a block diagram showing the functional structure of the control personal computer 23 of the variation. The difference from the control personal computer 22 (Figure 38) is that the control unit 201 includes a drawing pattern generation unit 212 and a pattern table generation unit 213 in addition to the processing unit 211.

The processing unit 211 is a functional block responsible for controlling the welding process of the workpiece W; the drawing pattern generating unit 212 is a functional block for generating a drawing pattern using the analysis result of the image processing unit 9; the pattern table generating unit 213 is a functional block for generating a pattern table using the analysis result of the image processing unit 9. Specifically, these functional blocks are implemented by computer programs. Here, the operation of the laser processing device of the variation example is explained using the flowcharts of Figures 47 and 48. First, the process starts with the workpiece W being set on the workpiece setting table 11.

The image processing unit 9 takes an image of the workpiece W (step S71). The image processing unit 9 uses the image taken in step S71 as a reference to analyze the pin arrangement of the workpiece W (step S72), and sends the analysis result to the control personal computer 23. The analysis result can also be sent to the control personal computer 23 in the form of a coordinate table 113. The pattern table generation unit 213 of the control personal computer 23 uses the analysis result of the workpiece W by the image processing unit 9 to generate a pattern table in which the pin number and the depicted pattern are associated, and the pin number shows the position of a pair of flat conductors 52 that are the welding objects (step S73). The pattern table generation unit 213 stores the generated pattern table in the memory unit 202.

Next, the drawing pattern generating unit 212 generates a drawing pattern using the analysis result of the workpiece W by the image processing unit 9 (step S74). Specifically, as shown in FIG. 41, the prohibited irradiation area is defined based on the positional relationship between the flat conductor 52 to be welded and the tall flat conductor 60 and the size of each pin, and a drawing pattern (pattern B and pattern C, etc.) is generated that excludes the prohibited irradiation area. Furthermore, the drawing pattern generating unit 212 generates pattern A belonging to the drawing pattern, and pattern A is used when the flat conductor 52 is not adjacent to the tall flat conductor 60. The drawing pattern generating unit 212 transfers the generated drawing pattern to the hybrid galvanometer scanner 10. In addition, the order of step S73 and step S74 may be reversed.

Next, various parameters of the first oscillator 2 and the second oscillator 3 are sent from the control personal computer 23 to the laser controller 14, and the laser controller 14 sets the parameters for each oscillator (step S75). Next, the workpiece setting table 11 is moved in such a way that the flat conductor 52 recorded in the first row of the pattern table faces the hybrid galvanometer scanner 10, thereby moving the workpiece W (step S76). The steps so far are the previous preparations for the welding process, and the welding process of the workpiece W is started below. The processing unit 211 of the control personal computer 23 refers to the pattern table stored in the memory unit 202 to determine whether the drawing pattern corresponding to the flat conductor 52 currently being the welding object is pattern A or pattern B (step S77). The processing control unit 211 sends a processing action instruction to the hybrid galvanometer scanner 10, and the processing action instruction includes information for identifying the processing pattern that has been identified.

In the case of pattern A, that is, when there is no high flat conductor 60 adjacent to the flat conductor 52, the hybrid oscillator scanner 10 that has received the processing action instruction selects pattern A (step S79). In the case of pattern B, that is, when there is a high flat conductor 60 adjacent to the flat conductor 52, the hybrid oscillator scanner 10 selects pattern B (step S80). Afterwards, a laser irradiation instruction is sent from PLC13 to the first oscillator 2 and the second oscillator 3. The first oscillator 2 and the second oscillator 3 that have received the laser irradiation instruction irradiate the first laser light L1 and the second laser light L2 respectively (step S81).

The laser irradiation of step S81 uses the welding method consisting of the three steps described in the first embodiment. In addition, as described above, the laser irradiation time and the laser irradiation position can also be controlled according to the configuration of a pair of flat conductors 52 that are welding objects. The hybrid galvanometer scanner 10 matches the irradiation position to the flat conductor 52 that is the next welding object (step S82). After step S82, the processing unit 211 determines whether one quarter of the processing of the object W has been completed (step S83). In the case where one quarter of the processing has not been completed (no in step S83), return to step S77 and continue processing.

When the processing of one quarter of the workpiece W is completed (yes in step S83), the processing unit 211 determines whether the overall processing has been completed (step S84). When the overall processing of the workpiece W is not completed (no in step S84), the processing unit 211 instructs the workpiece setting table 11 to rotate the workpiece W by one quarter through PLC13. The workpiece setting table 11, which has received the instruction from PLC13, drives the rotating mechanism (θ-axis table 11θ) and rotates the table by one quarter (step S85). After that, it returns to step S77 and continues processing. When the overall processing of the workpiece W is completed (yes in step S84), the laser processing device ends the welding processing of the workpiece W.

As described above, in the laser processing device of the variation, in addition to the functions described in the second embodiment, the image processing unit 9 analyzes the conditions near the flat conductor 52 to be welded. The control personal computer 23 generates a drawing pattern or a pattern table based on the analysis result. According to this variation, even if the object W to be processed has been changed, it is not necessary to input the drawing pattern and the pattern table corresponding to the changed object W to be processed. In addition, the arrangement of the flat conductor 52 and the flat conductor 60 is an example, and other arrangements are of course possible. For the flat conductor 52 to be welded, no matter where the flat conductor 60 is adjacent, the prohibited irradiation area shown in FIG. 41 can be specified, so that the welding process can be performed in a manner that the reflected light caused by the molten ball does not irradiate all the adjacent flat conductors 60.

For example, as shown in FIG. 49, consider a case where the four sides of the flat conductor 52 to be welded are surrounded by the high flat conductors 60. In this case, by reciprocating the irradiation in the oblique direction as shown in the trajectory I4, the welding process can be performed in a manner that the reflected light caused by the molten ball does not irradiate all of the four adjacent flat conductors 60. [Other Variations] (1) In the above-mentioned embodiment 1 and embodiment 2, the laser processing device may also have: a shielding gas nozzle that supplies shielding gas to the workpiece W. Moreover, nitrogen as a shielding gas is sprayed on the weld surface at 5L/min to 100L/min at the same time as the irradiation of the first laser light L1 and the second laser light L2, or from before the irradiation of the first laser light L1 and the second laser light L2 to the end of the irradiation or for a longer period of time. More preferably, the welding process is performed in a nitrogen atmosphere while blowing at 10L/min to 40L/min.

For example, two shielding gas nozzles can be used to spray nitrogen from the left and right sides of the workpiece W. The angle of each shielding gas nozzle relative to the workpiece W is an inclination angle of 0° to 90° relative to the end face. In order not to interfere with the operation of the hybrid galvanometer scanner 10, it is preferably about 30°. The diameter of the front opening of the shielding gas nozzle (nozzle tip diameter) is preferably about 1mm to 10mm. In addition, the working distance (working distance) from the front opening of the shielding gas nozzle to the workpiece W is preferably about 5mm to 15mm. In this way, nitrogen is supplied to the workpiece W through the shielding gas nozzle, so that the laser processing device 1 performs welding of the workpiece W in a nitrogen atmosphere. The shielding gas prevents oxidation of the welding surface, thereby suppressing the reduction of welding strength and the generation of porosity caused by oxidation of the welding surface. Furthermore, by appropriately selecting conditions such as the flow rate of the shielding gas, the nozzle tip diameter, and the working distance, the shaking of the molten ball can be suppressed and a beautiful molten ball can be formed.

In addition, it is also possible to configure an air knife to replace the shielding gas blowing. (2) In the above-mentioned embodiment 1 and embodiment 2, the trajectory of the laser irradiation in the first step is not limited to straight reciprocating irradiation. In the first step and the second step, the end face 52a of each flat conductor 52 can also be subjected to circular irradiation, and the end face 52a of each flat conductor 52 can also be subjected to elliptical irradiation. It is preferable to irradiate with a size and shape suitable for the end face of the flat conductor 52. For example, in the case of elliptical irradiation of the rectangular end face 52a, it is preferable to irradiate in a manner such that the long side direction of the rectangle becomes the long diameter of the ellipse. Thereby, heat energy can be effectively imparted to the end face 52a to promote melting.

(3) In the above-mentioned first embodiment, the following situation is used as an example for explanation: a pair of flat wires 52 are spaced apart in the x-axis direction, are positionally offset in the y-axis direction, and rotate in the θ direction. The scanning trajectory of the third step for other positional offsets is explained. (a) in FIG. 33 shows the scanning trajectory of the third step for a situation where there is a gap in the x-axis direction. (b) in FIG. 33 shows the scanning trajectory of the third step for a situation where there is a positional offset in the y-axis direction. In all cases, the center point of the registered processing graphic data 1100 (8-shaped) is matched with the AB pin coordinates and the processing graphic data 1100 is further rotated and/or stretched by the A pin coordinates and the B pin coordinates. This allows laser light to be irradiated with a scanning trajectory corresponding to the configuration of various A pins and B pins.

(4) In the first embodiment, although the laser scanning trajectory of the third step is in the shape of an 8, this is only an example and is not limited to the 8 shape. The third step can be performed as long as the following processing can be achieved: when the molten parts of the A pin and the B pin formed in at least the first step and the second step are combined, the molten parts are stirred and homogenized by passing through the scanning trajectory near the center of the combined molten parts. For example, as shown in (c), (d), and (e) in Figure 33, the scanning trajectory of the third step can also be a straight reciprocating irradiation across the A pin and the B pin. In this case, the processing graphic data showing the straight line is pre-registered in the memory unit 202 of the control personal computer 12, and the control unit 201 modifies the registered processing graphic data according to the configuration conditions of each pair. Specifically, the straight line is rotated in the θ direction and stretched in the x-axis direction in such a way that the center point of the straight line matches the AB pin coordinates and the starting point and the end point of the straight line match the A pin coordinates and the B pin coordinates. In this way, reciprocating straight line irradiation corresponding to the configuration conditions of each pair can be realized.

In the case where a pair of flat wires 52 is spaced apart or deviated in position in the x-axis direction, the y-axis direction, or the θ rotation direction, it is assumed that the area of the molten portion connected by the irradiation of the first step and the second step becomes smaller. Even in the case where the area of the molten portion becomes smaller, the laser light is irradiated with a scanning track passing through the center of the molten portion to suppress the leakage of the laser light from the gap. In this way, it is possible to suppress the carbonization and poor insulation caused by irradiating the coating portion at the bottom of the flat conductor with laser light.

(5) As described in the first embodiment, when a rapid temperature rise occurs on the workpiece W, sputtering will occur. Therefore, instead of irradiating the first laser light L1 and the second laser light L2 simultaneously, the workpiece W may be irradiated with only the first laser light L1 having a high absorption rate, and then the second laser light L2 may be additionally irradiated after a predetermined time. In this way, a rapid temperature rise of the workpiece W can be suppressed, thereby suppressing the occurrence of sputtering. Furthermore, the workpiece W whose temperature has been raised by the first laser light L1 can efficiently absorb the energy of the second laser light L2 by increasing the absorption rate of the wavelength of the second laser light L2, thereby helping to shorten the processing time. In this case, it is desirable to irradiate the second laser light L2 after a delay of more than 1 msec after irradiating the first laser light L1.

(6) In the first and second embodiments, the focusing diameter d1 of the first laser light L1 is not limited to 1050 μm. The focusing diameter d1 can be selected so that the area of the irradiation region of the first laser light L1 (focusing area, point area) becomes 1% to 30% of the total area of the workpiece W. In addition, the focusing diameter d2 of the second laser light L2 is not limited to 40 μm. The focusing diameter d2 of the second laser light L2 can be set to about 10 μm to 100 μm, and is preferably set to less than one tenth of the focusing diameter d1 of the first laser light L1. The focusing diameter of each laser beam depends on the core diameter of the transmission optical fiber, the focal distance of the collimated lens, and the focal distance of the focusing lens, and can be calculated as follows: focusing diameter = core diameter of the transmission optical fiber × (focal distance of the focusing lens / focal distance of the collimated lens). Therefore, by adjusting these optical systems, the focusing diameter of each laser beam can be changed.

(7) In the above-mentioned first and second embodiments, although the power of the laser in the first step, the second step, and the third step is the same, this is only an example. For example, the output power of the laser may be set to be weaker in the third step than in the first and second steps. Since the third step is a process for homogenizing the molten metal, it is not necessary to use the same power as in the first and second steps. Furthermore, when excessive energy is applied to the workpiece W in the third step, there is a possibility that the laser may leak from the joint. Therefore, the output power of the laser may be reduced or the focus may be changed to limit the energy applied to the workpiece W.

(8) In the above-mentioned embodiments 1 and 2, although the scanning speed of the first laser light L1 and the second laser light L2 is set to 500 mm/s, the scanning speed of the first laser light L1 and the second laser light L2 is not limited thereto, and can be in the range of 100 mm/s to 1000 mm/s. (9) The irradiation time of the first step, the second step, and the third step of the above-mentioned embodiments 1 and 2 is an example, and is of course not limited to the irradiation time described above. The irradiation time of the first step only needs to be the time for a part of the molten part formed on the end face 52a to enter the gap 53; the irradiation time of the second step only needs to be the time for a part of the molten part formed on the end face 52a to enter the gap 53; the irradiation time of the third step only needs to be the time for the two molten parts that have been combined to be uniform until one molten part is formed. These irradiation times can also be changed according to the size of the flat conductor to be welded, the interval of the gap, etc.

(10) In the above-mentioned embodiment, since the third step is to make the molten metal uniform, the power equivalent to that of the first step and the second step is not required. Furthermore, when excessive energy is given to the workpiece W in the third step, there is a possibility that the laser will leak from the already bonded molten portion. Therefore, the laser processing device 1 of the first embodiment can also achieve the processing of the third step by the following method. The first method is to shift the focal position of the first laser light L1 and the second laser light L2 to above the molten portion. Thereby, the power density in the weld surface is reduced along with the expansion (divergence) of the focusing diameter, thereby reducing the risk of laser leakage.

The second method is to reduce the output power of the first laser light L1 and the second laser light L2 compared to the first step and the second step. In this way, the power density in the weld surface can be reduced, thereby reducing the risk of laser leakage. The third method is to increase the irradiation speed of the first laser light L1 and the second laser light L2. Increasing the irradiation speed can reduce the unit area of the laser light passing through the weld surface and the irradiation amount per unit time (heat input). In this way, the risk of laser leakage can be reduced.

(11) In the above-mentioned embodiment, a critical value for the spacing amount and the deviation amount may be set. When there is a spacing or position deviation exceeding the critical value, the laser processing device 1 may determine that it is an "error (unable to weld)" and interrupt the processing, and then move to the welding process of the next pair of flat wires 52. In this case, the memory unit 202 of the control personal computer 12 may pre-memorize the critical value that serves as a reference for "error". The controller 103 of the image processing unit 9 or the control unit 201 of the control personal computer 12 measures the spacing amount and the deviation amount from the position information (coordinate value) of each flat wire 52. The control unit 201 may also compare the measured distance amount and deviation amount with the critical value stored in the memory unit 202 .

(12) In the above embodiment, although it is described that the first laser light L1 is multi-mode and the second laser light L2 is single-mode, this is an example, and the beam mode of each laser light is not limited. (13) In the above embodiment, the laser irradiation time for the high flat line 52 is longer than the laser irradiation time for the low flat line 52, and the difference is greater as the step difference Δz is greater. In this way, the laser processing device 1 makes the energy given to each flat line 52 different according to the difference in laser irradiation time, but this embodiment is an example. The laser processing device 1 of the present invention only needs to set the irradiation energy given to the high flat line 52 to be greater than the irradiation energy given to the low flat line 52.

In addition, when focusing on the circled range 1111 of the processing rate table 1100 shown in Figure 29, the laser irradiation time of 58msec belonging to the low flat line 52 is equivalent to the "standard energy" of the present invention, and the laser irradiation time of 76msec belonging to the high flat line 52 is equivalent to the "additional irradiation energy corresponding to the step amount applied to the standard irradiation energy" of the present invention.

(14) In the above embodiment, the first laser light L1 and the second laser light L2 are focused on the workpiece W (welding surface), but in the present invention, the first laser light L1 and the second laser light L2 can also be focused to a position within a range of ±2 mm from the welding surface in the vertical direction. (15) In the above embodiment, the first laser light L1 and the second laser light L2 are circular beams, but the beam shapes of the first laser light L1 and the second laser light L2 are not limited to this. For example, an elliptical beam or a rectangular beam can also be used. In this case, it is preferred to use the long side direction as the major diameter in the rectangular welding surface.

(16) In the above-mentioned embodiments 1 and 2, a stator coil is used as an example of a workpiece for explanation. However, the welding method and laser processing device 1 described above are not limited to the case of being used for welding stator coils. (17) In the above-mentioned embodiments 1 and 2, the optical axis of the first laser light L1 and the optical axis of the second laser light L2 are made consistent, and scanning is performed by a hybrid galvanometer scanner 10. However, the present invention is not limited to this, and the optical axis of the first laser light L1 and the optical axis of the second laser light L2 may not be consistent, and they can also be scanned separately by separate laser scanning optical systems (galvanometer scanners). That is, the present invention may also include the following structure: the laser processing device is equipped with two galvanometer scanners, one galvanometer scanner scans the first laser light L1, and the other galvanometer scanner scans the second laser light L2.

(18) In the above-mentioned laser processing device 1, the focusing diameter and output power of each of the first laser light L1 and the second laser light L2, and the irradiation trajectory, irradiation time, irradiation speed, and number of irradiations of the first step, the second step, and the third step can be inputted through the input unit 203 of the galvanometer scanner personal computer (controlling the personal computer 12), and the information can be pre-adapted to the size of the workpiece W. In addition, it can also be configured that when the workpiece size or the finished shape of the molten ball is inputted, the control unit 201 controlling the personal computer 12 determines the focusing diameter, output power, irradiation trajectory, irradiation time, irradiation speed, and number of irradiations of the laser according to a predetermined algorithm.

(19) In the above-mentioned second embodiment, it is assumed that the movable range of the hybrid galvanometer scanner 10 is about one-fourth of the size of the workpiece W. Therefore, the laser processing device performs the welding process of the entire workpiece W while rotating the workpiece W by one-fourth each time through the workpiece setting table 11. At this time, the position of the workpiece W is adjusted by the workpiece setting table 11 in such a way that the nozzle of the hybrid galvanometer scanner 10 is opposite to the approximate center of the area that has divided the workpiece W into four parts. Assuming that the movable range of the hybrid galvanometer scanner 10 can cover the entire workpiece W, the position can also be matched in such a way that the nozzle of the hybrid galvanometer scanner 10 is opposite to the center of the workpiece W.

In addition, in the case where the laser light is blocked by the high pin (flat conductor 60) and cannot be irradiated to the pin (flat conductor 52) to be welded, the workpiece setting table 11 is moved to adjust the position of the pin (flat conductor 52) to be welded so that it is arranged slightly directly below the nozzle of the hybrid galvanometer scanner 10. (20) In the above-mentioned second embodiment and the variation of the second embodiment, the laser processing device is configured to: maintain or create a plurality of drawing patterns, and select an appropriate drawing pattern according to the conditions near the flat conductor 52. However, the information maintained or created by the laser processing device of the second embodiment and the variation of the second embodiment is not limited to the drawing pattern. In addition to the drawing pattern, it can also be a welding pattern combined with the irradiation conditions of the laser. Furthermore, it is also possible to select an appropriate welding pattern according to the conditions near the flat conductor 52.

The irradiation conditions of the laser included in the welding pattern include, for example, the focusing diameter of the laser, the output power, the irradiation time, the irradiation speed, the number of irradiations, etc. (21) In the above-mentioned second embodiment, although the laser processing device generates a drawing pattern and a pattern table, the action of generating the drawing pattern is not necessary. The laser processing device can also only generate a pattern table based on the analysis result of the image processing unit 9. The user can also input the drawing pattern from the input unit 203 of the control personal computer 22.

(22) In the above-mentioned second embodiment and the variation of the second embodiment, it is not necessary that the wire close to the flat conductor 52 is a flat wire, and it can be a wire of other shapes. In addition, it is not necessary that the component close to the flat conductor 52 is a wire, and it can be another component. The laser processing device only needs to have at least the following structure: select a drawing pattern from a plurality of drawing patterns according to the peripheral conditions of a pair of flat conductors 52 that are the objects of welding, irradiate laser light with the selected drawing pattern, and perform welding processing. (23) Here, as a variation, Figures 50 and 51 are used to explain the welding process in the case where the position deviation of a pair of flat wires 52 to be welded is generated in the xyθ direction (in the case where there is no step difference in the z-axis direction).

First, the user operates the input unit 203 of the control personal computer 12 to input the processing graphic data 1100, and the control personal computer 12 registers the processing graphic data 1100 into the memory unit 202 (step S91). The processing graphic data 1100 is used for laser irradiation in the third step. Then, the workpiece W is set on the workpiece setting table 11. The workpiece setting table 11 carrying the workpiece W is moved, so that the workpiece W is arranged directly below the image processing unit 9. Then, the image of the workpiece W is captured by the shooting device 101 of the image processing unit 9 (step S92).

The controller 103 of the image processing unit 9 analyzes the image of the workpiece W taken in step S92, thereby measuring the coordinate values of all the flat lines 52 contained in the workpiece W (step S93). Then, the controller 103 records the measured coordinate values in the coordinate table 113 (step S94). Then, the control personal computer 12 sets the laser parameters for the first oscillator 2 and the second oscillator 3 through the laser controller 14 (step S95). The workpiece setting table 11 moves the workpiece W to the bottom of the hybrid galvanometer scanner 10.

In this variation, it is assumed that the scannable range of the hybrid galvanometer scanner 10 is about one-fourth of the size of the workpiece W. Therefore, the laser processing device 1 performs the overall welding of the workpiece W while rotating the workpiece W by one-fourth each time through the workpiece setting table 11. Hereinafter, the laser processing device 1 repeatedly processes from step S96 to step S105 for each quarter of the circumferential direction of the workpiece W. Furthermore, the laser processing device 1 repeatedly processes from step S97 to step S103 for each pair of flat wires 52 that are the welding objects. The control unit 201 controlling the personal computer 12 obtains a pair of coordinate values (pin A coordinates and pin B coordinates) currently being processed from the coordinate table 113 stored in the memory unit 104 of the image processing unit 9 (step S98).

The laser processing device 1 performs the processing of the first step (step S99), which is used to irradiate the first laser light L1 and the second laser light L2 to the flat wire 52 (A) on one side. Specifically, in the first step, a laser irradiation instruction is sent from the PLC 13 to the first oscillator 2 and the second oscillator 3 via the laser controller 14. The first oscillator 2 and the second oscillator 3 that have received the laser irradiation instruction irradiate the first laser light L1 and the second laser light L2 respectively. At about the same time, a control instruction is sent from the control unit 201 of the personal computer 12 to the hybrid galvanometer scanner 10 based on the A pin coordinates obtained in step S98. The hybrid galvanometer scanner 10 controls the scanning position in response to the control instruction.

The scanning trajectory of the hybrid galvanometer scanner 10 in the first step is straight reciprocating irradiation, and the first laser light L1 and the second laser light L2 are straight reciprocating irradiated at the predetermined position of the end face 52a. Preferably, the position near the butt joint 52b (position close to the spacing) in the end face 52a can also be straight reciprocatingly irradiated. In the first step, the laser irradiation is continued until the end face 52a of the A pin is completely melted. Then, the laser processing device 1 performs the second step (step S100), and the second step (step S100) is used to irradiate the first laser light L1 and the second laser light L2 to the other flat line 52 (B). The laser irradiation in the second step is the same as the first step. The hybrid galvanometer scanner 10 controls the scanning position based on the B pin coordinates obtained in step S98. The scanning trajectory of the hybrid galvanometer scanner 10 in the second step is a straight reciprocating irradiation. The first laser light L1 and the second laser light L2 are straight reciprocating irradiations of the predetermined position of the end face 52a. The second step is also the same as the first step. The position of the end face 52a close to the butt surface 52b (the position close to the spacing) can also be linearly reciprocated. In the second step, the laser irradiation is continued until the end face 52a of the B pin is completely melted.

In addition, the laser irradiation of the first step and the laser irradiation of the second step can also be performed simultaneously. When the molten portion of pin A is combined with the molten portion of pin B, the control unit 201 of the personal computer 12 corrects the processing pattern data 1100 stored in the memory unit 102 according to the configuration of pin A and pin B (step S101). The control unit 201 sends the corrected processing pattern data to the hybrid galvanometer scanner 10. Afterwards, the corrected processing pattern data is used to perform the processing of the third step (step S102), which is used to irradiate the first laser light L1 and the second laser light L2 across pin A and pin B. In the third step, heat energy is applied to pins A and B again to make the molten part uniform, thus forming a beautiful symmetrical molten ball. The third step can also be continued until the molten ball reaches the desired size.

The welding process is performed for all pairs of flat wires contained in one quarter of the workpiece W that is currently being processed. At this time, the welding process is performed while correcting the scanning trajectory of the third step according to the configuration status of each pair. When the welding process is completed for all pairs of flat wires contained in one quarter of the workpiece W, the control personal computer 12 instructs the workpiece setting table 11 to rotate the workpiece W by one quarter through PLC13. The workpiece setting table 11, which has received the instruction from PLC13, drives the rotating mechanism (θ-axis table 11θ) and rotates the table by one quarter (step S104). Then, it returns to step S97 and continues the process. The laser processing device 9 processes each quarter of the workpiece W, and when the welding process of all pairs of flat wires contained in the workpiece W is completed, the welding process of the workpiece W is completed.

(24) Here, as a variation example, FIG. 52 and FIG. 53 are used to explain the welding process in the case where a pair of flat wires 52 to be welded have a step difference in the z-axis direction (in the case where there is no positional deviation in the xyθ direction). First, the process starts with the workpiece W being set on the workpiece setting table 11. The workpiece setting table 11 carrying the workpiece W is moved, and the workpiece W is arranged directly below the image processing unit 9. Then, the image of the workpiece W is captured by the shooting device 101 of the image processing unit 9 (step S111). The controller 103 of the image processing unit 9 analyzes the image of the workpiece W captured in step S111, thereby measuring the coordinate values of all the flat wires 52 contained in the workpiece W (step S112). Next, the controller 103 records the measured coordinate values in the coordinate table 113 (step S113).

Next, the control personal computer 12 sends the processing graphic data to the hybrid galvanometer scanner 10, and sets the laser parameters for the first oscillator 2 and the second oscillator 3 through the laser controller 14 (step S114). The workpiece setting table 11 moves the workpiece W to the bottom of the hybrid galvanometer scanner 10 (step S115). In this embodiment, it is assumed that the scannable range of the hybrid galvanometer scanner 10 is about one-fourth of the size of the workpiece W. Therefore, the laser processing device 1 performs the overall welding processing of the workpiece W while rotating the workpiece W by one-fourth each time through the workpiece setting table 11. Hereinafter, the processing from step S116 to step S126 is repeated for each quarter of the circumferential direction of the workpiece W. Furthermore, the laser processing device 1 repeatedly processes from step S117 to step S125 for each pair of flat wires 52 to be welded.

The control unit 201 controlling the personal computer 12 obtains a pair of step difference Δz and spacing Δxy currently being processed from the image processing unit 9 (step S118). The control unit 201 refers to the processing rate table 110 stored in the memory unit 202 to obtain the laser irradiation time corresponding to the step difference Δz and spacing Δxy obtained in step S118. As described above, the processing rate table 110 records two values in a circled range, and the control unit 101 obtains the two values recorded in the upper and lower sections. The value recorded in the upper section is the irradiation time of the first step described later, and the value recorded in the lower section is the irradiation time of the second step described later (step S119).

Next, the control unit 201 of the personal computer 12 determines which flat line is higher in the pair currently being processed (step S120). This determination process is performed by receiving information such as the number for identifying the higher flat line from the controller 103 of the image processing unit 9, but it can also be performed by the control unit 201 reading the coordinate value from the coordinate table 113 stored in the image processing unit 9. Next, the laser processing device 1 performs the first step (step S121) of irradiating the higher pin with the first laser light L1 and the second laser light L2. Specifically, the control unit 201 for controlling the personal computer 12 sends the laser irradiation time obtained in step S119 to the laser controller 14, and sets the laser irradiation time for the first oscillator 2 and the second oscillator 3. Furthermore, the control unit 201 sends a control command to the hybrid galvanometer scanner 10, and the laser irradiation command is sent from the PLC 13 to the first oscillator 2 and the second oscillator 3 via the laser controller 14. The first oscillator 2 and the second oscillator 3 that have received the laser irradiation command irradiate the first laser light L1 and the second laser light L2, respectively.

The scanning trajectory of the hybrid galvanometer scanner 10 in the first step is a straight reciprocating irradiation. When the laser light is irradiated at the processing rate (irradiation time) obtained in step S9, the B pin is melted to a height slightly below the A pin, and a molten ball 55b is formed. Here, the first laser light L1 and the second laser light L2 are linearly reciprocating irradiated to a predetermined position of the end face 52a, preferably a position (close to the spacing) in the end face 52a close to the butt surface 52b. Then, the laser processing device 1 performs the second step (step S122), and the second step (step S122) is used to irradiate the low A pin with laser light. In the second step, the first laser light L1 and the second laser light L2 are irradiated to the welded surface of the A pin. At this time, the scanning trajectory of the hybrid galvanometer scanner 10 is a straight reciprocating irradiation like the first step. When the laser light is irradiated at the processing rate (irradiation time) obtained in step S119, the entire end surface 52a of the A pin is melted, and a molten ball is formed on the A pin.

In addition, the second step is similar to the first step, and the position near the butt joint 52b in the end face 52a (the position near the spacing) can also be linearly reciprocated. In this way, the laser light is irradiated near the inner side, thereby shortening the time until the molten part is combined. Then, before the processing of the third step, the focal position of the first laser light L1 and the second laser light L2 is offset to the height of the B pin before melting (step S123). After the two molten balls are combined, the laser processing device 1 performs the processing of the third step (step S124). In the third step, an elliptical or 8-shaped circular irradiation is performed across the A pin and the B pin. At this time, the hybrid galvanometer scanner 10 uses the center coordinates of the AB pin to adjust the position of the processing graphic data.

In the third step, heat energy is applied again to the B pin that has been previously laser irradiated, and the two molten balls are homogenized to form beautiful molten balls that are symmetrical on both sides. The third step can also be circularly irradiated instead of elliptically irradiated according to the size and shape of the flat wire 52. In this way, the third step is processed after the two molten balls are combined, thereby suppressing the leakage of laser light from the gap and causing damage to the lower part of the flat wire. When the welding process of a pair of flat wires contained in a quarter of the workpiece W that is currently being processed is completed, the control personal computer 12 instructs the workpiece setting table 11 to rotate the workpiece W by a quarter through the PLC 13. The workpiece setting table 11, which has received instructions from PLC13, drives the rotating mechanism (θ-axis table 11θ) to rotate the table by one quarter (step S126). Then, it returns to step S117 and continues processing.

The laser processing device 1 processes each quarter of the workpiece W, and when the welding process of all pairs of flat wires contained in the workpiece W is completed, the welding process of the workpiece W is completed. (25) Figures 35, 36 and 37 are specific examples of UI screens displayed on the display unit 205 of the control personal computer 12 belonging to the galvanometer scanner personal computer. Figure 35 is a diagram showing an example of a main screen 160, which displays the coordinate values of each pin and the laser processing conditions. Figure 36 is a diagram showing an example of a processing graphic data registration screen 170. Figure 37 is a diagram showing an example of a processing position confirmation screen 180, which displays the situation where the registered processing graphic data is corrected and configured.

(26) Here, a system for measuring a plurality of measurement objects is described with reference to the drawings. The type of measurement object is not particularly limited, and any object can be used. Here, objects of the same shape are assumed. In addition, the so-called "measurement" refers to the measurement of: the presence or absence of an object, the number of objects, the area of an object, the length and circumference of an object, the position of an object, defects of an object, and the characteristics of its shape. Here, as an example, the situation of measuring the number of measurement objects is described. The measurement system 1000 of Figure 54 includes: a tray 1003, which carries a plurality of measurement objects 1002; an illumination device 1004, which irradiates the plurality of measurement objects 1002 with illumination light; a photographing device 1005, which photographs the measurement objects illuminated by the illumination device 1004; a measurement device 1006, which uses the image data photographed by the photographing device 1005 to measure the measurement objects 1002; and a monitor 1009, which outputs the measurement results. The photographing device 1005 and the measuring device 1006 may be used as an image processing device in an integrated structure, and the lighting device 1004, the photographing device 1005 and the measuring device 1006 may be used as an image processing device in an integrated structure.

As shown in FIG54, the measuring device 1006 includes a memory 1007 and a processor 1008. The memory 1007 stores a measuring program, and the processor 1008 executes the measuring program, thereby the measuring device 1006 performs a measuring process of the measuring object. Here, as a specific example, as shown in FIG54, a case of measuring a plurality of measuring objects 1002 placed on a tray 1003 is described. FIG55 is a diagram of the tray 1003 viewed from above (vertical direction) of the drawing. Before the measuring process performed by the measuring device 1006, first, the photographing device 1005 photographs the measuring object 1002 on the tray 1003 illuminated by the lighting device 1004. The measuring device 1006 obtains the captured image data and performs the measuring process shown in FIG. 56 based on the image data.

First, the measuring device 1006 performs the first binary large object analysis processing on the image data (step S201). The so-called binary large object analysis is a type of image analysis, which is used to perform a binarization process on each pixel contained in the image data that is the object, and use the image data after the binarization process to perform various analyses and measurements. Figure 57 is a diagram showing the image data 100a after the binarization process. In addition, although the image data after the binarization process is represented by two color levels of white and black, for the convenience of explanation, black is marked with a hatching pattern in Figure 57 and the like. The results of the binarization process of the sixteen measurement objects 1002 in Figure 55 are represented in Figure 57 as twelve binary large objects, namely binary large objects B1 to binary large objects B12. The reason is that the closely connected measurement object 1002 is represented as a large binary object through binarization processing. In this state, even if various measurements such as quantity and area are performed, correct measurement results will not be obtained.

Therefore, the measuring device 1006 calculates the area of each binary large object contained in the image data 100a (step S203), and compares the calculated area with a preset threshold value. In this way, it is determined whether the measured objects have been combined with each other. The threshold value used for comparison can be set according to the area of the measured object 1002. In the case where the area of the binary large object is less than the threshold value (no in step S204), the processing of step S205 is skipped and the process moves to step S206. When the area of the binary large object is larger than the threshold value (yes in step S204), a mask area is arranged on the binary large object to be the target, and the binary large object is segmented (step S205). For example, when segmenting the binary large object B1 (center position is P1) shown in (a) of FIG. 58, a mask area of a thin and long shape including the center position P1 (x, y) and parallel to the y axis is arranged on the image data as shown in (b) of FIG. 58. The mask area is an area that is not recognized in image processing, and the line width only needs to be about one pixel to two pixels.

Since the measuring device 1006 is based on the premise of measuring the quantity of the measuring object 1002, as an example, an area is formed that includes the center position P1 and is parallel to the y-axis, but the setting method of the mask area is not limited to this. It can be appropriately changed according to what is to be measured. Then, the measuring device 1006 performs the second binary large object analysis process (step S207) to obtain the image data 100b shown in Figure 59. In the image data 100b, the binary large object B1 is divided into a binary large object B13 and a binary large object B14, the binary large object B10 is divided into a binary large object B15 and a binary large object B16, and the binary large object B11 is divided into a binary large object B17 and a binary large object B18. The measuring device 1006 measures the number of binary large objects in the image data 100b (step S208). In the first binary large object analysis process, the number of binary large objects is measured as twelve; in the second binary large object analysis process, the number of binary large objects is measured as sixteen. The measuring device 1006 outputs the measured number of binary large objects as the number of the measurement object 1002 to the monitor 1009.

Thus, the measuring device 1006 of the measuring system 1000 performs two binary large object analysis processes, thereby being able to accurately measure the measuring object 1002. (27) The above-mentioned implementation form 1, implementation form 2 and the above-mentioned variations can also be appropriately combined. (28) In addition, in the above-mentioned implementation form, each component can also be implemented by executing a software program suitable for each component. Each component can also be implemented by the program execution unit of the CPU or processor reading and executing the software program recorded on the recording medium such as a hard disk or a semiconductor memory.

In addition, each component can also be implemented by hardware. For example, each component can also be a circuit (or integrated circuit). These circuits can be formed as a whole circuit, or they can be independent circuits. In addition, these circuits can be general-purpose circuits or dedicated circuits. In addition, the overall aspect or specific aspect of the present invention can also be implemented by a system, device, method, integrated circuit, computer program, or computer-readable CD-ROM (Compact Disc Read Only Memory). In addition, it can also be implemented by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media. In addition, the present invention can also be implemented as a non-temporary recording medium that is readable by a computer and records such a program.

In addition, as long as they do not deviate from the spirit and scope of the present invention, various variations that can be thought of by a person of ordinary knowledge in the relevant technical field are applied to the aspects of this embodiment and the aspects formed by combining the constituent elements in different embodiments are also included in the scope of one or more aspects of the present invention. [Appendix] Part or all of the above embodiments and variations can be interpreted in the following manner.

(Appendix 1) A welding method is used to arrange the end faces of the first component and the second component after the ends are butted against each other to face the laser processing device, and weld the end faces by laser light; the welding method comprises: a first step of irradiating the first component with the laser light to form a first molten portion; a second step of irradiating the second component with the laser light to form a second molten portion; and a third step of irradiating the first molten portion and the second molten portion that have been combined with each other with the laser light to form a single molten portion when the first molten portion and the second molten portion are combined; the laser light is composed of a first laser light and a second laser light having different wavelengths.

(Appendix 2) The welding method as described in Appendix 1, wherein the focal diameter of the second laser light is smaller than the focal diameter of the first laser light; the first step is to irradiate the predetermined position of the first component in a substantially straight line back and forth, thereby forming the first molten portion; the second step is to irradiate the predetermined position of the second component in a substantially straight line back and forth, thereby forming the second molten portion; the third step is to irradiate the laser light across the first component and the second component when the first molten portion and the second molten portion are combined.

(Appendix 3) The welding method as described in Appendix 2, wherein in the first step and the second step, the predetermined position is a position close to the butting surface of the first component and the second component. (Appendix 4) The welding method as described in Appendix 1, wherein the third step is to scan the laser light across the first component and the second component in any shape of an ellipse, a circle, a polygon, a straight line or an eight-shaped shape.

(Appendix 5) The welding method as described in Appendix 1, wherein the third step is to irradiate the laser light to a fixed point approximately in the center between the first molten portion and the second molten portion that have been bonded. (Appendix 6) The welding method as described in Appendix 1, wherein the wavelength of the first laser light is 300nm to 600nm. (Appendix 7) The welding method as described in Appendix 6, wherein the focusing area of the first laser light is 1% to 30% of the total area of the end face.

(Appendix 8) The welding method as described in Appendix 6, wherein the output power of the first laser light and the second laser light is 500W to 3kW. (Appendix 9) The welding method as described in Appendix 6, wherein the energy density of the laser irradiated in the third step is lower than the energy density of the laser irradiated in the first step and the second step.

(Appendix 10) The welding method as described in Appendix 1, wherein there is a gap between the first component and the second component; the irradiation time of the first step is the time until a part of the first molten portion enters the gap; the irradiation time of the second step is the time until a part of the second molten portion enters the gap; the irradiation time of the third step is the time until the first molten portion and the second molten portion that have been bonded are homogenized.

(Appendix 11) The welding method as described in Appendix 1, wherein the wavelength of the second laser light is 780nm to 1100nm. (Appendix 12) The welding method as described in Appendix 11, wherein the focusing diameter of the second laser light is less than one tenth of the focusing diameter of the first laser light. (Appendix 13) The welding method as described in Appendix 11, wherein the focusing diameter of the second laser light is 10μm to 100μm.

(Appendix 14) A welding method as described in Appendix 1, wherein the first component and the second component are flat conductors with rectangular cross sections for forming a coil for a stator; the ends of the two flat conductors arranged opposite to the laser processing device are butted and welded by the laser light and the second laser light, thereby forming a molten ball on the end surface. (Appendix 15) A welding method as described in Appendix 1, wherein nitrogen is sprayed on the end surface at a flow rate of 5L/min to 100L/min and at an inclination angle of 0° to 90° relative to the end surface, simultaneously with the irradiation of the first laser light and the second laser light, or from before the irradiation of the first laser light and the second laser light to the end of the irradiation or for a longer period of time.

(Appendix 16) A laser processing device is used to weld the end faces of the first component and the second component that have been butted together, and comprises: a first oscillator that oscillates a first laser light; a second oscillator that oscillates a second laser light having a wavelength different from that of the first laser light; one or more galvanometer scanner units that displace the first laser light and the second laser light to any direction and irradiate; and a control unit that controls the first oscillator, the second oscillator, and the oscillator. Mirror scanner unit; the laser processing device irradiates the first component with the first laser light and the second laser light to form a first melting part, irradiates the second component with the first laser light and the second laser light to form a second melting part, and when the first melting part and the second melting part are combined, the first melting part and the second melting part that have been combined are irradiated with the first laser light and the second laser light to form a melting part.

(Appendix 17) The laser processing device as described in Appendix 16, wherein the laser processing device irradiates the predetermined position of the first component with the first laser light and the second laser light in a substantially straight line to form the first melting portion, and irradiates the predetermined position of the second component with the first laser light and the second laser light in a substantially straight line to form the second melting portion, and when the first melting portion and the second melting portion are combined, the first laser light and the second laser light are irradiated across the first component and the second component. (Appendix 18) The laser processing device as described in Appendix 17, wherein the laser processing device further comprises: a synthesizer section for superimposing the first laser light and the second laser light on the same optical axis; and a galvanometer scanner section for irradiating the first laser light and the second laser light with the same optical axis to the first component and the second component.

(Appendix 19) The laser processing device as described in Appendix 17, wherein the laser processing device is further provided with: an input unit for accepting input from a user; the input unit for accepting various parameters for controlling the first oscillator, the second oscillator and the galvanometer scanner unit, and outputting the accepted parameters to the control unit; the control unit for controlling the first oscillator, the second oscillator and the galvanometer scanner unit based on the parameters obtained through the input unit.

(Appendix 20) A welding method as described in Appendix 1, wherein in the case where there is a gap between the first component and the second component, the molten portion formed by the end surface of each of the first component and the second component being melted by the laser light enters the gap, whereby the laser light is irradiated with a predetermined scanning trajectory passing through the vicinity of the center of the already bonded molten portions in a state where the two previously bonded molten portions have been bonded. (Appendix 21) A welding method as described in Appendix 20, wherein the aforementioned welding method includes the following steps: using an image processing unit to obtain position information of the first component and the second component; and controlling the scanning of the laser light based on the obtained position information.

(Appendix 22) The welding method as described in Appendix 1, wherein there is a step difference between the end faces of the first component and the second component due to positional deviation in the height direction; the first step is to irradiate the end face of the higher one of the first component and the second component with laser light to melt the end face; the second step is to irradiate the end face of the lower one of the first component and the second component with laser light to melt the end face; the melting amount of the first step is greater than the melting amount of the second step.

(Appendix 23) The welding method as described in Appendix 22, wherein the aforementioned welding method further includes the following steps: using the image processing unit to detect the height of the aforementioned first component and the aforementioned second component. (Appendix 24) The welding method as described in Appendix 23, wherein the aforementioned welding method further includes the following steps: using the aforementioned image processing unit to obtain the step difference between the aforementioned first component and the aforementioned second component; in the aforementioned first step, adding the additional irradiation energy corresponding to the step difference to the reference irradiation energy to irradiate the laser light; in the aforementioned second step, irradiating the laser light with the reference irradiation energy.

(Appendix 25) A welding method is used to weld the two flat wires by butting the front ends of the two flat wires and irradiating the end faces with laser light; there is a step difference between the two end faces due to the positional deviation of the two flat wires in the height direction; the welding method comprises: a first step of irradiating the end face of the higher flat wire with laser light to melt the end face; and a second step of irradiating the end face of the lower flat wire with laser light to melt the end face; the amount of melting in the first step is greater than the amount of melting in the second step.

(Appendix 26) The welding method as described in Appendix 25, wherein the aforementioned welding method further includes the following steps: using the image processing unit to detect the height of the two aforementioned flat wires. (Appendix 27) The welding method as described in Appendix 26, wherein the aforementioned welding method further includes the following steps: using the aforementioned image processing unit to obtain the step difference between the two aforementioned flat wires; in the aforementioned first step, adding the additional irradiation energy corresponding to the step difference to the reference irradiation energy to irradiate the laser light; in the aforementioned second step, irradiating the laser light with the reference irradiation energy.

(Appendix 28) The welding method as described in Appendix 27, wherein the aforementioned reference irradiation energy is determined by at least one of the power of the aforementioned laser processing device, the laser wavelength, the size of the aforementioned flat wire, and the material of the flat wire. (Appendix 29) The welding method as described in Appendix 27, wherein the aforementioned reference irradiation energy is the energy required for the overall melting of the end surface of the aforementioned flat wire.

(Appendix 30) The welding method as described in Appendix 27, wherein the additional irradiation energy is greater as the step difference is greater. (Appendix 31) The welding method as described in Appendix 27, wherein there is a gap between the two flat wires due to positional deviation; the welding method further comprises the following steps: using the image processing unit to obtain a spacing amount, the spacing amount indicating the size of the gap between the two flat wires; in the first step, adding the additional irradiation energy corresponding to the step difference and the spacing amount to the reference irradiation energy to irradiate the laser light; in the second step, adding the additional irradiation energy corresponding to the spacing amount to the reference irradiation energy to irradiate the laser light.

(Appendix 32) The welding method described in Appendix 31, wherein the additional irradiation energy is greater as the distance between the two flat wires is greater. (Appendix 33) The welding method described in Appendix 30 or Appendix 32, wherein the laser processing device stores a table, wherein the table stores additional energies corresponding to the step amount and the distance amount; and the welding method determines the additional energy by referring to the table.

(Appendix 34) The welding method as described in Appendix 25, wherein the aforementioned welding method further comprises: a third step, after the aforementioned second step, irradiating the laser light across the two aforementioned flat wires and stirring the molten portion. (Appendix 35) The welding method as described in Appendix 34, wherein in the aforementioned third step, the energy of the laser light irradiated to the molten portion in a manner that the aforementioned laser light does not leak below the molten portion is smaller than the energy of the laser light irradiated in the aforementioned first step and the aforementioned second step.

(Appendix 36) The welding method as described in Appendix 35, wherein in the aforementioned third step, the focal position of the aforementioned laser light is shifted to above the aforementioned molten portion. (Appendix 37) The welding method as described in Appendix 25, wherein in the aforementioned first step and the aforementioned second step, the aforementioned laser light is reciprocated to irradiate a predetermined position near the butt surface in the end face of each flat wire.

(Appendix 38) A laser processing device is used to butt the front ends of two flat wires of different heights and irradiate the end faces with laser light to perform butt welding of the front ends; the laser processing device comprises: an image processing unit for detecting the height of the two flat wires; a first oscillator for oscillating a first laser light; a second oscillator for oscillating a second laser light having a wavelength different from that of the first laser light; and one or more oscillating mirror scanner units for displacing the first laser light and the second laser light. to any direction and irradiate; and a control unit controls the first oscillator, the second oscillator and the galvanometer scanner unit; the laser processing device irradiates the end face of the high flat wire with the first laser light and the second laser light to melt the end face, and then irradiates the end face of the low flat wire with the first laser light and the second laser light to melt the end face; the melting amount of the high flat wire is greater than the melting amount of the low flat wire.

(Appendix 39) A welding method is used to butt the front ends of two flat wires and make the end faces face the laser processing device, and irradiate the end faces with laser light, thereby welding the two flat wires; in the above welding method, when there is a gap between the two flat wires, the molten part formed by the end faces of each of the two flat wires being melted by the above laser light enters the above gap, so that the above laser light is irradiated with a predetermined scanning trajectory passing through the center of the already combined molten parts in a state where the two above molten parts have been combined. (Appendix 40) The welding method as described in Appendix 39, wherein the above welding method includes the following steps: using an image processing unit to obtain position information of the two flat wires; the above welding method controls the scanning of the above laser light based on the obtained above position information.

(Appendix 41) The welding method as described in Appendix 40, wherein the welding method uses the obtained position information to measure the middle point of the two flat wires; and irradiates the laser light with the scanning track that crosses the two flat wires and passes through the middle point. (Appendix 42) The welding method as described in Appendix 40, wherein the welding method uses the obtained position information to measure the center point of the end face of each of the two flat wires; and irradiates the laser light with the scanning track that crosses the two flat wires and passes through the center point of each end face of the two flat wires.

(Appendix 43) A welding method as described in Appendix 40, wherein the welding method irradiates the laser light with the scanning track of a figure 8 that crosses two of the flat lines. (Appendix 44) A welding method as described in any one of Appendixes 41 to 43, wherein the laser processing device holds processing graphic data, and the processing graphic data displays the predetermined scanning track; the welding method further includes the following step: using the obtained position information to match the state of the gap to correct the processing graphic data.

(Appendix 45) The welding method as described in Appendix 39, wherein in an xy orthogonal coordinate system with an arbitrary point on the table on which the flat wires are placed as the origin, the gap is generated in the following situations: when the two flat wires are relatively offset in the x-axis direction; when the two flat wires are offset in the y-axis direction; when the two flat wires are offset in both the x-axis direction and the y-axis direction; or when the two flat wires are relatively rotated in the xy plane.

(Appendix 46) The welding method as described in Appendix 45, wherein the aforementioned welding method further comprises the following steps: detecting the relative deviation of the two aforementioned flat wires based on the aforementioned position information obtained; comparing the detected deviation with a preset threshold value; and when the detected deviation exceeds the aforementioned threshold value, determining that welding is not possible.

(Appendix 47) The welding method as described in Appendix 39, wherein the focal position of the aforementioned laser light is shifted to above the aforementioned molten portion. (Appendix 48) The welding method as described in Appendix 39, wherein the aforementioned molten portion that has been bonded is stirred by the aforementioned laser light to form a molten ball of a desired size or shape.

(Appendix 49) A welding method is used to weld the two flat wires by butting the front ends of the two flat wires together and making the end faces face the laser processing device, and irradiating the end faces with laser light, thereby welding the two flat wires; in the welding method, there is a positional deviation between the two flat wires, and when the end faces of the two flat wires are melted by the laser light and the molten parts formed are already joined, the laser light is irradiated with a predetermined scanning track passing through the vicinity of the center of the already joined molten parts.

(Appendix 50) A laser processing device is used to butt the front ends of two flat wires and irradiate the end faces with laser light to perform butt welding of the front ends; the laser processing device comprises: an image processing unit for detecting position information of the two flat wires; a first oscillator for oscillating a first laser light; a second oscillator for oscillating a second laser light having a wavelength different from that of the first laser light; and one or more oscillating mirror scanner units for displacing the first laser light and the second laser light to any direction. and irradiating toward the two flat wires; and a control unit controls the first oscillator, the second oscillator and the galvanometer scanner unit; the laser processing device is to irradiate the two flat wires with a predetermined scanning track passing through the vicinity of the center of the two fused parts when a gap exists between the two flat wires and the molten part formed by the end surface of each of the two flat wires melted by the laser light enters the gap, and the two fused parts are already combined.

(Appendix 51) A method for manufacturing a stator is used to manufacture a stator for use in a motor; the stator comprises: a cylindrical stator core having a plurality of grooves arranged in a circumferential direction; and a plurality of flat conductors inserted into the grooves and joined to each other to form a segmented coil; the method for manufacturing the stator comprises making the end faces of two corresponding flat conductors butt against each other and facing a laser processing device, selecting a welding pattern from a plurality of welding patterns according to the peripheral conditions of the corresponding two flat conductors, and irradiating the end faces with laser light with the selected welding pattern, thereby welding the end faces.

(Appendix 52) A method for manufacturing a stator as described in Appendix 51, wherein the welding pattern is selected according to whether there are other components near the two flat conductors to be welded. (Appendix 53) A method for manufacturing a stator as described in Appendix 52, wherein the welding pattern is a drawing pattern for showing the irradiation trajectory of the laser light in the end surface; when there are no other components near the two flat conductors to be welded, the laser light is irradiated with a first drawing pattern; when there are other components near the two flat conductors to be welded, the laser light is irradiated with a second drawing pattern different from the first drawing pattern.

(Appendix 54) A method for manufacturing a stator as described in Appendix 53, wherein the processing time in the case of welding by irradiating the laser light with the first drawing pattern is shorter than the processing time in the case of welding by irradiating the laser light with the second drawing pattern. (Appendix 55) A method for manufacturing a stator as described in Appendix 54, wherein the protrusion of the other components from the axial end surface of the stator core is greater than that of the flat conductor; the first drawing pattern is an irradiation trajectory for accelerating the melting of the flat conductor; and the second drawing pattern is an irradiation trajectory for suppressing the molten ball generated on the end surface of the flat conductor from reflecting the laser light, thereby causing the reflected light of the laser light to irradiate the components.

(Appendix 56) A method for manufacturing a stator as described in Appendix 55, wherein the method for manufacturing the stator is that when the laser light passes through the weld surface, the area where the reflected light is irradiated onto the component is formulated as a prohibited irradiation area; the second depiction pattern is an irradiation track for excluding the prohibited irradiation area from the weld surface.

(Appendix 57) The manufacturing method of the stator as described in Appendix 56, wherein the manufacturing method of the stator is to use at least one of the distance between the two flat conductors to be welded and the components located near the two flat conductors, the size of the components, the size of the molten ball, the curved surface shape of the molten ball, and the area of the welded surface to determine the prohibited irradiation area. (Appendix 58) The manufacturing method of the stator as described in Appendix 57, wherein the other components are wires used for conducting electricity to the outside.

(Appendix 59) The manufacturing method of the stator as described in Appendix 52, wherein the aforementioned laser light is a hybrid laser light, and the aforementioned hybrid laser light is formed by superimposing a first laser light and a second laser light of different wavelengths on the same optical axis. (Appendix 60) The manufacturing method of the stator as described in Appendix 59, wherein the wavelength of the aforementioned first laser light is 300nm to 600nm; the wavelength of the aforementioned second laser light is 780nm to 1100nm.

(Appendix 61) A method for manufacturing a stator as described in Appendix 60, wherein the second depiction pattern is irradiated with the laser light in an 8-shaped trajectory across the two flat conductors to be welded. (Appendix 62) A method for manufacturing a stator as described in Appendix 60, wherein the second depiction pattern is irradiated with the laser light in an oblique direction across the two flat conductors to be welded.

(Appendix 63) The manufacturing method of a stator as described in Appendix 61 or Appendix 62, wherein the first depiction pattern is to irradiate the laser with a predetermined rotation diameter across the two flat conductors to be welded. (Appendix 64) The manufacturing method of a stator as described in Appendix 63, wherein the manufacturing method of the stator is to select the first depiction pattern or the second depiction pattern while referring to information for indicating the arrangement state between the plurality of flat conductors to be welded and other components.

(Appendix 65) A method for manufacturing a stator as described in Appendix 64, wherein the method for manufacturing the stator is to analyze the stator by image processing and generate the aforementioned information for displaying the arrangement state between the plurality of flat conductors and the other components to be welded. (Appendix 66) A laser processing device is used to manufacture a stator used in a motor; the stator comprises: a cylindrical stator core having a plurality of grooves arranged in a circumferential direction; and a plurality of flat conductors inserted into the grooves and joined to each other to form a segmented coil; the laser processing device comprises: a first oscillator for oscillating a first laser light; a second oscillator for oscillating a second laser light having a wavelength different from that of the first laser light; a synthesizer unit for superimposing the first laser light and the second laser light on the same optical axis; a galvanometer scanning unit; The device part displaces the first laser light and the second laser light whose optical axes are aligned to any direction and irradiates; the stage carries the stator so that the end faces of the two corresponding flat conductors are butted against each other and face the galvanometer scanner part; and the control part controls the first oscillator, the second oscillator and the galvanometer scanner part to select a welding pattern from a plurality of welding patterns according to the peripheral conditions of the two corresponding flat conductors, and irradiates the end faces with laser light with the selected welding pattern to weld the end faces.

(Appendix 67) The laser processing device as described in Appendix 66, wherein the aforementioned laser processing device is further equipped with: an input unit for inputting information for displaying the arrangement status of the plurality of aforementioned flat conductors and other components in the aforementioned stator; and a memory unit for storing the inputted aforementioned information; and the aforementioned control unit for selecting one aforementioned welding pattern from the plurality of aforementioned welding patterns with reference to the aforementioned information stored in the aforementioned memory unit. (Appendix 68) The laser processing device as described in Appendix 66, wherein the aforementioned laser processing device is further equipped with: an image processing unit for analyzing the arrangement of the plurality of aforementioned flat conductors and other components in the aforementioned stator; and a memory unit for storing the analysis results of the aforementioned image processing unit; the aforementioned control unit selects one aforementioned welding pattern from the plurality of aforementioned welding patterns with reference to the aforementioned analysis results stored in the aforementioned memory unit.

(Appendix 69) A laser processing device comprises: a synthesizer section for superimposing a plurality of laser lights of different wavelengths on the same optical axis; a focus shifter section for adjusting the focal distance of the laser lights superimposed by the synthesizer section; and a galvanometer scanner section located downstream of the focus shifter section for shifting the direction of the optical axis of the laser light toward the object to be processed; the laser processing device synchronizes the adjustment of the focal distance by the focus shifter section with the displacement of the direction of the optical axis by the galvanometer scanner section.

(Appendix 70) A laser processing device as described in Appendix 69, wherein there is no lens for passing the laser light between the galvanometer scanner section and the object to be processed. (Appendix 71) A laser processing device as described in Appendix 69 or Appendix 70, wherein the focus shifter section has a lens for adjusting the focal distance of the same laser light by moving forward and backward along the optical axis of the laser light; the laser processing device is configured such that the synthesizer section is downstream of the lens of the focus shifter section.

(Appendix 72) A laser processing device as described in Appendix 69, Appendix 70 or Appendix 71, wherein the focus shifter section comprises: a lens for expanding the diameter of the laser light overlapped by the synthesizer section; and a lens for reducing the diameter of the laser light that has passed through the same lens; the laser processing device expands and reduces the relative distance between the two lenses along the optical axis of the laser light in synchronization with the displacement of the direction of the optical axis by the galvanometer scanner section. (Appendix 73) A laser processing device as described in Appendix 69 or Appendix 70 or Appendix 71 or Appendix 72, wherein the object to be processed is irradiated with laser light to perform welding; the laser light on which the blue laser light and the infrared laser light are superimposed is irradiated onto the object to be processed via the aforementioned synthesizer unit, the aforementioned focus shifter unit, and the aforementioned galvanometer scanner unit.

1: Laser processing device 2: First oscillator 3: Second oscillator 4: Synthesizer 6: Focus shifter 8: Vibration mirror scanner 9: Image processing unit 10,10a,10b: Hybrid vibration mirror scanner 11: Workpiece setting table 11a: Base 11x: x-axis table 11y: y-axis table 11z: z-axis table 11θ: θ-axis table 12,22,23: Control PC (Vibration mirror scanner PC) 13: PLC 14: Laser controller 15: Fixing fixture 31,32: Lens 33,34: Mirror 41: Lens (concave lens, biconcave lens) 42: Lens (convex lens, collimating lens) 43: Lens (convex lens, focusing lens) 50: Stator 51: Stator core 52: Flat conductor (flat wire) 52a: Welding surface (end surface) 52b: Butt surface 53: Gap 54: First molten portion (groove) 55: Second molten portion 55,55a,55b,55c: Molten ball 57: xy plane 58: Insulation coating 60: Flat conductor 81,82,83,84: Mirror 100: Control panel 100a,100b, 120a, 120b, 120c: Image data 101: Lighting device 102: Camera device 103: Controller 104: Memory 105: Processor 110: Processing graphic data 111: Measurement program 112: Threshold value 113: Coordinate table 121: Drawing pattern 122: Pattern table 150: Login screen 151: Work list 152: Processing point list 153: Processing image 154: Laser parameter input unit 155: Login button 160: Main screen 170: Processing graphic data login screen 180: Processing position confirmation screen 201: Control unit 202: Memory unit 203: Input unit 204: Communication unit 205: Display unit 211: Processing unit 212: Drawing pattern generation unit 213: Pattern table generation unit 1000: Measurement system 1002: Measurement object 1003: Tray 1004: Lighting device 1005: Camera device 1006: Measurement device 1007: Memory 1008: Processor 1009: Monitor 1100: Processing rate table (processing graphic data) 1112: Circle selection range B1 to B18, B21 to B25: Binary large object D: Relative distance d1, d2: Converging diameter e, O: Center F: Focus distance I1, I2, I3, I4, I7, I8, I9: trajectory L1: first laser beam L2: second laser beam L3: reflected light P21, P22, P23: center position R21, R22, R23: circle S11 to S19, S21 to S33, S51 to S63, S82 to S85, S91 to S105, S111 to S127, S201 to S209: steps W: workpiece θ: angle Δz: step difference (step difference amount) Δxy: spacing (spacing amount)

[FIG. 1] is a diagram showing the appearance of the laser processing device 1. [FIG. 2] is a diagram showing the functional structure of the laser processing device 1. [FIG. 3] is a diagram showing the structure of the hybrid galvano scanner 10. [FIG. 4] is a diagram for explaining the function of the focusing shifter unit 6. [FIG. 5] is a diagram for explaining the function of the galvano scanner unit 8. [FIG. 6] is a diagram showing the structure of a hybrid galvano scanner 10a belonging to a variation. [FIG. 7] is a diagram showing the structure of a hybrid galvano scanner 10b belonging to a variation. [FIG. 8] is a three-dimensional diagram showing the schematic structure of a stator belonging to a workpiece. (a) to (c) in [Fig. 9] are diagrams for explaining the position deviation of the flat wire (segmented coil) 52 in the xyθ direction. [Fig. 10] is a diagram for explaining the step difference in the z direction of the flat wire 52. [Fig. 11] is a block diagram showing the functional configuration of the image processing unit 9. [Fig. 12] is a diagram for explaining the coordinate values measured by the image processing unit 9. [Fig. 13] is a diagram for explaining the coordinate values measured by the image processing unit 9. [Fig. 14] is a block diagram showing the functional configuration of the control personal computer 12. [Fig. 15] is a flowchart showing the operation of the laser processing performed by the laser processing device 1. [Fig. 16] is a diagram showing an example of the login screen 150. [Fig. 17] is a flowchart showing the operation of the measurement processing performed by the image processing unit 9. [Figure 18] is a flowchart showing the operation of the measurement processing performed by the image processing unit 9. [Figure 19] is a diagram for explaining labeling (numbering). [Figure 20] is a diagram for explaining the first binary large object analysis processing (blob analysis processing) (height binarization). [Figure 21], (a) shows the image data of the center position measured by the first binary large object analysis processing, (b) is a diagram for explaining the setting of the mask area, and (c) is a diagram for showing the image data of the center position measured by the second binary large object analysis processing. [Figure 22] is a diagram for explaining the height measurement processing. [Figure 23] is a diagram showing the data structure of the coordinate table 113. In [Figure 24], (a) is a diagram showing the trajectory of laser irradiation in the first step, (b) is a diagram showing the trajectory of laser irradiation in the second step, and (c) is a diagram showing the trajectory of laser irradiation in the third step. [Figure 25] (a) to (f) are diagrams for explaining the shape change of the workpiece W (weld surface). [Figure 26] (a) to (d) are diagrams showing the variation example of the third step. [Figure 27] is a diagram for explaining the effect of the variation example of the third step. [Figure 28] is a flow chart showing the action of laser processing. [Figure 29] is a diagram showing the structure of the data of the processing rate table 1100. In [Figure 30], (a) is a schematic diagram for explaining the processing of the first step when there is a step difference, (b) is a schematic diagram for explaining the processing of the second step when there is a step difference, and (c) is a schematic diagram for explaining the processing of the third step when there is a step difference. In [Figure 31], (a) is a schematic diagram for explaining the processing of the first step when there is a positional deviation in the xyθ direction, (b) is a schematic diagram for explaining the processing of the second step when there is a positional deviation in the xyθ direction, and (c) is a schematic diagram for explaining the processing of the third step when there is a positional deviation in the xyθ direction. [Figure 32] is a diagram for explaining the correction of the processed graphic data. In [Figure 33], (a) to (e) are diagrams for explaining the variation example of the third step. In [Figure 34], (a) to (c) are schematic diagrams for explaining the changes of the weld surface from the start of processing to the end of processing, and (d) is a schematic diagram showing the weld surface after processing in the known example. [Figure 35] is a diagram showing an example of the main screen 160. [Figure 36] is a diagram showing an example of the processing graphic data registration screen 170. [Figure 37] is a diagram showing an example of the processing position confirmation screen 180. [Figure 38] is a block diagram showing the functional structure of the control personal computer 22 of the second embodiment. [Figure 39], (a) is a three-dimensional diagram showing the schematic structure of the stator belonging to the welding object of the second embodiment, and (b) is an enlarged view of the flat wires 52, 52 of the second embodiment. [Figure 40] is a diagram for explaining the reflection of laser light during processing. [Figure 41] is a diagram for explaining the prohibited irradiation area. [Figure 42] is a diagram for explaining the drawing pattern. [Figure 43] is a diagram showing an example of the configuration of the flat line. [Figure 44] is a diagram showing the data structure of the pattern table. [Figure 45] is a flowchart showing the operation of processing. [Figure 46] is a block diagram showing the functional structure of the control personal computer 23 of the variation of the second embodiment. [Figure 47] is a flowchart showing the operation of processing of the variation of the second embodiment. [Figure 48] is a flowchart showing the operation of processing of the variation of the second embodiment. [Figure 49] is a diagram for explaining the variation of the drawing pattern of the second embodiment. [Figure 50] is a flowchart showing the operation of the variation of the laser processing (xyθ position deviation). [Figure 51] is a flowchart showing the operation of a variation of the laser processing (xyθ position deviation). [Figure 52] is a flowchart showing the operation of a variation of the laser processing (z-direction step difference). [Figure 53] is a flowchart showing the operation of a variation of the laser processing (z-direction step difference). [Figure 54] is a diagram showing the system configuration of the measurement system 1000. [Figure 55] is a diagram for explaining the state of the measurement object 1002 placed on the tray 1003. [Figure 56] is a flowchart for explaining the operation of the measurement program. [Figure 57] is an image data showing the result of the first binary large object analysis process. [Figure 58] is a diagram for explaining the setting of the mask area. [Figure 59] shows the image data of the result of the second binary large object analysis process.

1: Laser processing equipment

2: First oscillator

3: Second oscillator

10: Hybrid vibrating mirror scanner

11: Workpiece setting table

11a: Abutment

11x:x axis stage

11y:y-axis stage

11z: z-axis stage

11θ:θ axis table

12: Control personal computer (mirror scanner personal computer)

15: Fixing fixture

100: Control panel

101: Lighting equipment

102: Filming equipment

203: Input Department

205: Display unit

Claims (20)

A welding method is used to arrange the end faces of the first component and the second component after the ends are butted against each other to face the laser processing device, and weld the end faces by laser light; The welding method comprises: A first step is to irradiate the first component with the laser light to form a first molten portion; A second step is to irradiate the second component with the laser light to form a second molten portion; and A third step is to irradiate the first molten portion and the second molten portion that have been combined with the laser light when the first molten portion and the second molten portion are combined to form a molten portion; The laser light is composed of a first laser light and a second laser light having different wavelengths. The welding method as described in claim 1, wherein the focusing diameter of the second laser light is smaller than the focusing diameter of the first laser light; The first step is to irradiate the predetermined position of the first component in a substantially straight line back and forth, thereby forming the first molten portion; The second step is to irradiate the predetermined position of the second component in a substantially straight line back and forth, thereby forming the second molten portion; The third step is to irradiate the laser light across the first component and the second component when the first molten portion and the second molten portion are combined. A welding method as described in claim 2, wherein in the first step and the second step, the predetermined position is a position close to the mating surface in the first component and the second component. The welding method as recited in claim 1, wherein the third step is to scan the laser light across the first component and the second component in any shape of an ellipse, a circle, a polygon, a straight line or an eight-shaped shape. The welding method as recited in claim 1, wherein the third step is to irradiate the laser light to a fixed point approximately at the center between the first molten portion and the second molten portion that have been bonded. The welding method as described in claim 1, wherein the wavelength of the first laser light is 300nm to 600nm. In the welding method as recited in claim 6, the focusing area of the first laser light is 1% to 30% of the total area of the end face. The welding method as described in claim 6, wherein the output power of the first laser light and the second laser light is 500W to 3kW. A welding method as recited in claim 6, wherein the energy density of the laser irradiated in the aforementioned third step is lower than the energy density of the laser irradiated in the aforementioned first step and the aforementioned second step. The welding method as described in claim 1, wherein there is a gap between the first component and the second component; The irradiation time of the first step is the time until a part of the first molten portion enters the gap; The irradiation time of the second step is the time until a part of the second molten portion enters the gap; The irradiation time of the third step is the time until the first molten portion and the second molten portion that have been bonded are homogenized. A welding method as described in claim 1, wherein the wavelength of the second laser light is 780nm to 1100nm. A welding method as described in claim 11, wherein the focusing diameter of the second laser light is less than one tenth of the focusing diameter of the first laser light. The welding method as described in claim 11, wherein the focusing diameter of the second laser light is 10 μm to 100 μm. The welding method described in claim 1, wherein the first component and the second component are flat conductors with rectangular cross-sections for forming a coil for a stator; The ends of the two flat conductors arranged opposite to the laser processing device are butted and welded by the laser light and the second laser light, thereby forming a molten ball on the end surface. A welding method as described in claim 1, wherein in a case where there is a gap between the first component and the second component, a molten portion formed by melting the end faces of each of the first component and the second component by the laser light enters the gap, whereby the laser light is irradiated along a predetermined scanning trajectory passing through the vicinity of the center of the two molten portions that have been combined, in a state where the two molten portions have been combined. The welding method as described in claim 15, wherein the welding method comprises the following steps: using an image processing unit to obtain position information of the first component and the second component; controlling the scanning of the laser light based on the obtained position information. The welding method as described in claim 1, wherein there is a step difference caused by positional deviation in the height direction on the end faces of the first component and the second component; The first step is to irradiate the end face of the higher one of the first component and the second component with laser light to melt the end face; The second step is to irradiate the end face of the lower one of the first component and the second component with laser light to melt the end face; The melting amount of the first step is greater than the melting amount of the second step. The welding method as described in claim 17, wherein the welding method further comprises the following step: using an image processing unit to detect the height of the first component and the second component. The welding method as described in claim 18, wherein the welding method further comprises the following steps: using the image processing unit to obtain the step difference between the first component and the second component; In the first step, adding the additional irradiation energy corresponding to the step difference to the baseline irradiation energy to irradiate the laser light; In the second step, irradiating the laser light with the baseline irradiation energy. A laser processing device is used to weld the end faces of the first component and the second component that have been butted together, and comprises: A first oscillator that oscillates a first laser light; A second oscillator that oscillates a second laser light having a wavelength different from that of the first laser light; One or more galvanometer scanner units that displace the first laser light and the second laser light to any direction and irradiate; and A control unit that controls the first oscillator, the second oscillator, and the galvanometer scanner unit; The laser processing device irradiates the first component with the first laser light and the second laser light to form a first melting portion, irradiates the second component with the first laser light and the second laser light to form a second melting portion, and when the first melting portion and the second melting portion are combined, the combined first melting portion and the second melting portion are irradiated with the first laser light and the second laser light to form a melting portion.

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